Catalase Production Research Articles

Variovorax soli mediated growth amelioration and abiotic stress alleviation in Capsicum annuum

In present study, rhizobacterial strains were isolated from soil sample and screened for plant growth promoting and antagonistic potential in vitro condition. The isolate exhibiting maximum plant growth promoting and antagonistic potential was subjected to biochemical characterization and 16S rDNA gene sequencing. Based on molecular characterization, the isolate was identified as Variovorax soli with NCBI accession number LC372534. The PGP potential of Variovorax soli was established as it augmented plant growth in control and under salt, drought, heavy metal stress conditions. Positive results for in-vitro tests viz. amylase, hydrogen cyanide, lipase, catalase, protease and chitinase production confirmed the antagonistic efficacy of Variovorax soli. Nutrient acquisition enhancing efficiency of V. soli was established as positive results were recorded for PGP tests viz. siderophore production, nitrogen fixation, phosphate solubilization and exopolysaccharide production. Plants inoculated with V. soli induced phytohormonal modulation (viz. increase in IAA level and reduction in stress ethylene level) for enhanced shoot, root length, increased plant fresh and dry weight, chlorophyll and proline content for extensive root system, plant growth and alleviation of salt, drought, arsenic stress impact as compared to uninoculated plants, thus confirming its ability as biological fertilizers. Along with (IAA) indole 3-acetic acid and (ACC deaminase) 1-aminocyclopropane 1-carboxylic acid deaminase, certain other extracellular exudates of PGPR serve as signaling molecules to trigger abiotic stress responsive pathway. V. soli is therefore a promising green alternative to chemical fertilizers to induce abiotic stress tolerance and reclaim soil fertility to elevate agricultural productivity.

Isolation and characterization mercury-resistant bacteria from gold mining in Lebong, Bengkulu

Lebong a regency in Bengkulu Province, possesses prominent potential in gold mining. This mining activity is conducted through amalgamation techniques, resulting in the deposition of mining residue containing mercury, subsequently leading to environmental pollution. Recognizing the hazards associated with such pollution, it becomes imperative to mitigate the presence of mercury through effective remediation strategies. Bioremediation, utilizing Mercury Resistant Bacteria (MRB), widely known as a viable method for mitigating mercury contamination. This study aims to isolate and characterize MRB to facilitate their potential application in addressing heavy metal pollution. This study involved the isolation and characterization of MRB through morphological observations, Gram staining, and biochemical tests (glucose, sucrose, fructose, citrate utilization, starch hydrolysis, urease activity, and catalase production). A total of 43 bacterial isolates were obtained from water, sediment, and soil samples collected from surrounding gold mining waste disposal. Among these isolates, bacteria resistant to mercury were selected on NA supplemented with various concentrations of mercury. Five potential candidates of MRB were identified, with the highest mercury concentration tested being 1000 ppm. Based on identification using Bergey’s Manual of Determinative Bacteriology, it was determined that four out of the five isolates belonged was Pseudomonas, while another belonged to Staphylococcus.

Isolation and Identification of Dextran-Producing Weissella cibaria from Pickled Sauerkraut

The presence of certain bacteria in food products are particularly desirable. Probiotic strains of lactic acid bacteria (LAB), which have a number of favorable characteristics, including antimicrobial properties that support the development of beneficial microflora, are among them. In addition, because of their biochemical activity, they have an impact on the dietary, nutritional, and organoleptic qualities of food products. Before being released into the market, each strain must undergo independent testing to ascertain its probiotic qualities and potency. The purpose of this study was to separate and identify the LAB strain (Weissella cibaria bacteria) at the molecular level from a sample of pickled Sauerkraut that might be employed in the dairy sector and maybe is regarded as a probiotic in the future. Directly from the can, the shredded picked sauerkraut was brined in 2.25% salt (NaCl) for 48 hours before being inoculated aseptically into deMan, Rogosa, and Sharpe agar (MRS) and incubated for two days at 37 °C. Gram’s reaction, catalase production, and sugar fermentation tests employing glucose, sucrose, maltose, lactose, and fructose were among the traditional assays performed on isolation. The sequence was acquired and checked against those in the GenBank database using the BLAST tool at the NCBI-GenBank database after the isolate was extracted using the AccuPrep Genomic DNA Extraction kit, amplified, and agarose gel electrophoresis. The isolated LAB strains were validated using SEM and a genetic PCR assay, and the matching rate of the two isolated strains was 99%. The obtained strains showed their ability to produce dextran by observing the viscous growth characteristic when they were grown in MRS medium supplemented with 15% sucrose. To identify the bacterium, many culture and biochemical tests were carried out. The overall study concluded that the strains of Weissella cibaria bacteria can be easily isolated from pickled Sauerkraut using the developed procedure with the possibility of using the dextran produced by the bacteria as a prebiotic in the food sector.

Bacillus Strains with Catalase Enzyme Improve the Physiology and Growth of Rice (Oryza sativa L.)

Catalase can decompose hydrogen peroxide in plants under controlled and stressed conditions. In a stressed environment, an increase in hydrogen peroxide production makes catalase activity a major defense system for plant growth. The current study was conducted to evaluate the catalase activity of the pre-isolated and identified bacterial strains Bacillus aryabhattai (AN30), Bacillus megaterium (AN24), Bacillus megaterium (AN31) and Bacillus megaterium (AN35) and their potential for rice seedling growth promotion. These strains were characterized for quantitative catalase, urease, siderophore and exopolysaccharide production using LB media. Subsequently, the effectiveness of these strains was checked by quantifying the catalase activity in the rhizosphere, roots and shoots of rice seedlings. The secretion of organic and phenolic compounds produced by the tested strains in liquid culture was also investigated. Plant growth parameters were also studied in a growth room trial. Our results showed that the strain AN24 showed the maximum catalase activity (1.36 mol cm−1), urease activity (1.35 mol cm−1) and exopolysaccharide (4.20 µg mL−1) and siderophore (2.32%) production in LB media. All tested strains showed significantly higher catalase activity in soil compared to the control. Among sole applications, strain AN24 showed better results; however, the consortium application of strains AN24 + AN30 + AN35 + AN31 showed the maximum improvement in dry biomass, shoot and root length, and increase in catalase activity of rice seedlings. The results showed that a consortium of these Bacillus strains with catalase activity has greater potential to enhance the antioxidant defense system and growth promotion of rice seedlings. However, further experimentation under natural conditions is required before using these strains as potential bioinoculants for improving rice growth and yield.

New report of endophytic bacterium Achromobacter xylosoxidans from root tissue of Musa spp.

Cavendish (AAA) banana plant (Musa spp.) worldwide cultivated crop harbors many endophytic bacteria. Endophytic bacteria are those that live inside plant tissues without producing any visible symptoms of infection. Endophytic bacterium (MRH 11), isolated from root tissue of Musa spp.was identified as Achromobacter xylosoxidans(ON955872) which showed positive effects in IAA production, phosphate solubilization, catalase production. A. xylosoxidans also showed in vitro antagonism against Curvularia lunata causing leaf spot disease of Cavendish (AAA) banana (G-9 variety). The GC-MS analysis of culture filtrate of A. xylosoxidans(ON955872) confirmed this finding. GC-MS analysis was carried by using two solvent etheyl acetate and chloroform and it showed several antifungal compounds. The identification of these bioactive secondary metabolites compounds was based on the peak area, retention time, molecular weight, molecular formula and antimicrobial actions. GC-MS analysis result revealed the presence of major components including Cyclododecane, 1-Octanol, Cetene, Diethyl phthalate. In vivo test to banana plants was carried out in separate field as well as in potted conditions. Appearance of leaf spots after foliar spray of spore of pathogen and reduction in leaf spots after application of bacterial suspension was found. The present study has highlighted the role of endophytic bacterium as antagonist to the pathogen Curvularia lunata.

The dynamics of microorganisms and their association with clam in fresh water ecosystem

Clams are shelled marine or fresh water mullusks belonging to the class Bivalvia. They are invertebrates with shells divided into two pieces called valves. They are rich source of proteins and minerals especially calcium and are recommended in the diet of pregnant women and in protein deficient cases. They inhabit the bottom of fresh water bodies or slow running waters. Fresh water is one which contain less than 0.5 parts per thousand of dissolved salts or other impurities, and are found in fresh water lakes, swamps and some rivers. The deposition of litter, substrates and other faecal materials in water body results in a build-up of pathogenic microorganism (bacteria) in the water which gives high burden on the water inhabitants including clams. The concentration of the bacteria in the water body varies with the season. This research was therefore aimed at accessing the type and density of bacteria and fungi present in fresh water associated with clams, and to determine the effect of the microorganism on the nutritional value of clams over a period of ten months in a fresh water ecosystem. Samples for analysis were water from Itu river, labeled sample A, sample B was water used to rinse the clams, sample C was homogenized clam intestine while sample D was homogenized body of the clam. The microbial load was determined using serial dilution and plating methods. Characterization and identification of microbial isolates was done using different standard biochemical tests, to determine; colonial morphology, Gram staining reaction, spore stain, motility, sugar fermentation, production of indole, coagulase and catalase. The methods as outlined by Association of Official Analytical Chemistry were used for physicochemical and nutritional analysis to test for moisture content, ash content, crude protein, fibre, fats and mineral elements. Results of the various analysis showed that, the total microbial count for the four samples through the ten months sampling period was highest in February with sample C having the highest of 1.2 X 105 cfu/mL, followed by sample D 7.0 X 104 cfu / mL, sample B had 5.8 X 104 cfu / mL while sample A was the lowest with 4.4 X 104 cfu / mL. The count was lowest in the month of September with C having 3.7 X 104 cfu / mL, followed by D with 2.4 X 104 cfu / mL, B had 8.0 X 103 cfu / mL while A the lowest was 4.0 X 103 cfu / mL. Microorganisms present in the fresh water sample and clam were mostly coliform from faecal matter and include; Staphylococcus aureus, Enterobacter aerogenes, Spirosoma lingual, Bacillus cereus, Lactobacillus plantarum, Escherichia coli, Flavobacterium aquatile and Micrococcus varians. We conclude that microbial load was higher in dry season than in rainy season probably due to dilution of the water and its velocity during rainy season. Results also showed that the nutritional values of the clam varies with season and density of microbial load. We recommend proper sanitation in water where clams are harvested and proper boiling of clams and possible removal of the intestine before consumption especially during the dry season.

Heavy metal-resistant rhizobacteria fosters to alleviate the cadmium toxicity in Arabidopsis by upregulating the plant physiological responses

This study was designed to investigate the role of Morganella morganii strains in alleviating Cd stress in Arabidopsis seedlings under controlled conditions. Both M. morganii strains ABT3 (ON316873) and ABT9 (ON316874) strains isolated from salt-affected areas showed higher resistance against Cd and possess plant growth-promoting traits such as nitrogen fixation, indole-acetic acid production, ammonia production, phosphate solubilization, and, catalase, gelatinase and protease enzyme production. Plant inoculation assay showed that varying concentration of Cd (1.5 mM and 2.5 mM) significantly reduced Arabidopsis growth, quantum yield (56.70%-66.49%), and chlorophyll content (31.90%-42.70%). Cd toxicity also triggered different associations between lipid peroxidation (43.61%-69.77%) and enzymatic antioxidant mechanisms. However, when both strains were applied to the Arabidopsis seedlings, the shoot and root length and fresh and dry weights were improved in the control and Cd-stressed plants. Moreover, both strains enhanced the resistance against Cd stress by increasing antioxidant enzyme activities [catalase (19.47%-27.39%) and peroxidase (37.50%-48.07%)]that ultimately cause a substantial reduction in lipid peroxidation (27.71%-41.90%). Both strains particularly ABT3 also showed positive results in improving quantum yield (73.84%-98.64%) and chlorophyll content (41.13%-48.63%), thus increasing the growth of Arabidopsis seedlings. The study suggests that PGPR can protect plants from Cd toxicity, and Cd-tolerant rhizobacterial strains can remediate heavy metal polluted sites and improve plant growth.

Exogenous foliar application of melatonin mitigates salt induced oxidative stress and promotes growth in Gerbera jamosonii

Salt stress is a major abiotic stress factor that is increasing at a continuos pace and pressurizing global food security in view of climate change. Therefore, plant scientists are developing strategies to ameliorate the negative effects of salt stress on crop production. Melatonin (N-acetyl-5-methoxytryptamine; MT) is a vital biological hormone in plants that modulates growth, development, and tolerance to extreme environmental conditions. Its exogenous application is used to improve resistance to various stressors. Gerbera (Gerbera jamosonii L. cv. Yunnanhong) is a vital ornamental flower crop moderately sensitive against salt stress. A series of experiments were conducted on gerbera plants grown under NaCl stress (150 mM) with or in the absence of MT at 0.1 and 0.2 mM. It was shown that salt stress reduced growth and physiological traits but also caused oxidative stress, as recorded by the induction of oxidative stress markers in cell tissues. Foliar application of MT, especially at the concentration of 0.2 mM, boosted plant growth, biomass production, photosynthetic pigments, and ameliorated oxidative stress. The decrease in oxidative stress was associated with improved antioxidant activity linked to the production of the enzymes catalase (CAT), superoxide dismutase (SOD), and peroxidase (POD). Exogenous MT also improved potassium (K+) uptake and restricted sodium (Na+) uptake in the leaves of gerbera. In conclusion, optimal MT application may serve as a potential ameliorator of salt-induced oxidative stress and help in the regulation of salinity for gerbera production under the threat of climate change.

Safety aspects, probiotic potentials of yeast and lactobacillus isolated from fermented foods in North-Eastern India, and its anti-inflammatory activity.

Lactobacillus and yeast obtained from fermented foods in North-East India were tested for safety and probiotic properties. All the lactobacilli and yeast tested negative for the catalase, indole, urease, phenylalanine, hemolysis, gelatin hydrolysis, and biogenic amine production tests, indicating that they are safe to use as probiotics in food supplements. Lactiplantibacillus plantarum KGL3A (accession no. MG722814) was capable of resisting the replicated gastric fluid (pH 2) till 2 h of exposure, whereas both KGL3A and Lacticaseibacillus rhamnosus K4E (accession no. KX950834.1) strains were able to resist pH 3 till 2 h of exposure with a reduction in overall viable cell count from 7.48 log CFU/mL to 1.09 log CFU/mL and 7.77 log CFU/mL to 0.83 log CFU/mL, respectively. In vitro gastric juice simulation conditions were tolerated by the yeast Saccharomyces cerevisiae WBS2A. The cell surface hydrophobicity (CSH) towards hydrocarbons (n-hexadecane) was seen highest in L. plantarum KGL3A (77.16± 0.84%) and Limosilactobacillus fermentum KGL4 accession no. MF951099 (72.60 ± 2.33%). The percentage auto-aggregation ranged from 8.70 to 25.53 after 2 h, which significantly increased to 10.50 to 26.94 during the fifth hour for cultures. Also, a higher percentage of co-aggregation was found for the culture L. rhamnosus K4E with S. typhi (34.18 ± 0.03%), E. coli (32.97 ± 0.02 %) and S. aureus (26.33 ± 0.06 %) and for the yeast S. cerevisiae WBS2A, a higher percentage of co-aggregation was found with Listeria monocytogenes (25.77 ± 0.22%). The antioxidant activity and proteolytic activity were found to be higher for Lactobacillus helveticus K14 and L. rhamnosus K4E. The proportion of decreased cholesterol was noticeably higher in KGL4 (29.65 ± 4.30%). β glucosidase activity was significantly higher in the L. fermentum KGL4 strain (0.359 ± 0.002), and α galactosidase activity was significantly higher in the L. rhamnosus K4E strain (0.415 ± 0.016). MTT assays suggested that KGL4 and WBS2A at a lower dose did not exhibit cytotoxicity.

Semi-solid enzymolysis enhanced the protective effects of fruiting body powders and polysaccharides of Herinaceus erinaceus on gastric mucosal injury

This study demonstrated the effects of semi-solid enzymolysis on physicochemical properties of fruiting body powders and polysaccharides from Hericium erinaceus and protective effects on gastric mucosal injury. Semi-solid enzymolysis could reduce the particle size, change the microstructure of fruiting body powders, increase the contents of soluble polysaccharide (26.26–67.04 %) and uronic acid (16.97–31.12 %) and reduce the molecular weight of polysaccharides. The digestibility of fruiting body powder of H. erinaceus after semi-solid enzymolysis was increased by 31.4 %, compared with that of the fruiting body powder of H. erinaceus without enzymolysis. Semi-solid enzymolysis could enhance the protective effects of the fruiting body powders and polysaccharides on ethanol-induced human gastric mucosal epithelial cells (GES-1) cells, increase the production of superoxide dismutase (SOD, 0–37.33 %) and catalase (CAT, 2.47–18.46 %), and inhibit the production of malonaldehyde (MDA, 2.45–19.62 %), myeloperoxidase (MPO, 0–13.54 %), interleukin (IL-6, 4.39–24.62 %) and tumor necrosis factor-α (TNF-α, 5.97–12.25 %). Semi-solid enzymolysis could improve the inhibition rate of the fruiting body powder on gastric ulcer (32.70–46.26 %), inhibit oxidative stress and inflammation, and protect rats with acute gastric mucosal injury against the stimulation of ethanol on gastric mucosa. In conclusion, semi-solid enzymolysis may enhance the protective effects of the fruiting body powders and polysaccharides on gastric mucosal injury.

Plant growth-promoting traits and activation of defense enzymes in traditional rice variety by fungal endophytes isolated from seeds of indigenous rice cultivars of Northeast India

The present investigation was carried out to expound on the role of seed borne endophytic fungi isolated from native rice cultivars of North East India. Altogether 226 fungal isolates were obtained from the surface-sterilized seeds of the 10 selected rice cultivars. The major isolates were species of Curvularia, Aspergillus, Fusarium, Gliocladium, Mucor, Penicillium, Bipolaris, Basidiobolus, Periconia, and non-sporulating mycelia sterilia. Principal Component Analysis (PCA) revealed dominance of Fusarium and Curvularia with high degree of colonization in Ampack and Chakhao rice cultivars. Altogether 84.61% of the isolates, showed siderophores activity on CAS agar medium and 76.92% of the isolates showed phosphorus solubilization activity. The result indicated that 84.61% of the isolates showed positive for ammonia production and interestingly grew in nitrogen-deficient Jensen's agar medium. The fungal isolates BD9, KON7, AM34, AM10, and Mycelia sterilia exhibited the highest antagonistic activity against rice pathogen Magnaporthe grisea. Enhanced production of peroxidase, polyphenol oxidase, chitinase, and superoxide dismutase enzyme was observed when a traditional rice plant was inoculated with a consortium made of fungal isolates AM34 and AM10 (Treatment 3). This combination exhibited a moderate increase in catalase production. Consortia made of other fungal isolates were not efficient in producing any defense enzymes. The isolates AM10, AM28, AM16, AM34, and AN 20 were identified as Fusarium annulatum, Daldinia eschscholtzii, Montagnula scabiosae, Fusarium redolens and Aspergillus flavus respectively based on microscopic and molecular characterization

Efficacy evaluation of newly isolated zinc solubilizing bacteria for their potential effect on maize (Zea mays L.) under zinc deficient soil conditions

AbstractZinc solubilizing bacteria (ZSB) induces the conversion of fixed and unavailable soil zinc to readily available zinc contributes plant zinc nutrition and fortification. The present research intended to determine the screening of plant growth‐promoting (PGP) traits of potent ZSB, biochemical and molecular characterization of ZSB, and assessment of potent ZSB for crop yield at the field level. Therefore, in the present study, molecular and functional characterization of native ZSB isolates was done to examine their response to plant growth performance and yield, mobilization of zinc, and acquisition by maize plants. Zinc solubilizing bacterial isolates namely, ZSB1, and ZSB 17 were solubilized insoluble zinc namely, ZnCO3, ZnO, Zn3(PO4)2 and significantly induced growth performance of maize crop at field conditions. A biochemical study revealed that both ZSB isolates were positive for catalase and urease production. Isolates ZSB1 & ZSB17 showed different PGP attributes like production of Indole‐3‐acetic acid (IAA), siderophore, NH3, and HCN. Both isolates were solubilized phosphate, potassium, and silica and showed 1‐aminocyclopropane‐1‐carboxylate (ACC)‐deaminase activity. 16S rRNA amplification and sequence study of ZSB1 and ZSB17 revealed that both the isolates were Cupriavidus sp. and Pantoea agglomerans, respectively, and novel. The results elucidated from pot studies demonstrated that both ZSB1 & ZSB17 were the more suitable isolates than other ZSB isolates, and these isolates were further tested for field studies. Cupriavidus sp. and Pantoea agglomerans strains increased Zn‐translocation toward grains and yield of Maize (cv: P3441) by 19.01% and 17.64%, respectively. We conclude that the novel indigenous ZSB strains substantially heightened zinc mobilization, the yield of maize crop, restore soil health, and can be suitable for biofortification and biofertilizers technology.

Isolation, estimation of bacterial load, and characterization of gut microbes of three Garra species from Bhavani river, Western ghats,Tamil Nadu, India

Microbiomes play an important role in fish physiology, particularly in digestion, by metabolizing largely indigestible feed components for the host or synthesis of essential micronutrients. The gut flora has a dynamic effect on the host’s gut and systemic immunity. This study is the preliminary exploration of gut microflora of three species Garra mcclellandi, Garra stenorhynchus, and Garra gotyla stenorhynchus . The total bacterial load ranges from 66×108 CFU/g to 81×108 CFU/g in the gut sample. It was found that the maximum load in G. stenorhynchus with 81×108 CFU/g followed by Gg. stenorhynchus with 72×108 CFU/ml minimum in G. mcclellandi with 66×108 CFU/ml. The isolates were subjected to various biochemical characterizations such as the Indole test, Voges Proskauer test, Methyl Red test, Carbohydrate Utilization Test, Citrate Utilization Test, Starch Hydrolysis, and Catalase Production activity. The three fish gut samples are screened for antagonistic properties for certain human pathogens which show zero antagonistic activities. The present preliminary study shows variation in the gut microflora and these microbes may be used for the development of probiotics and drug production.

Bilayered skin substitute incorporating rutin nanoparticles for antioxidant, anti-inflammatory, and anti-fibrotic effect

Hypertrophic scarring in large burns and delayed healing in chronic wounds are consequences of prolonged and aggravated inflammation, sustained infiltration of immune cells, free radical generation, and abundance of inflammatory mediators. Therefore, it is imperative to curb hyperinflammation to expedite wound healing. In this study, rutin nanoparticles (RNPs) were synthesized without an encapsulant and incorporated into eggshell membrane powder-crosslinked gelatin-chitosan cryogels to impart antioxidant and anti-inflammatory properties for treating hyperinflammation. The resultant nanoparticles were found to be 17.53 ± 4.03 nm in size and were stable at room temperature for a month with no visible sedimentation. RNPs were found to be non-cytotoxic and exhibited anti-inflammatory (by increasing IL-10 levels) and antioxidant properties (by controlling the generation of reactive oxygen species and enhancing catalase production in human macrophages). Additionally, RNPs were found to reduce α-SMA expression in fibroblasts, thereby demonstrating their anti-scarring effect. In vivo studies with a bilayered skin substitute constituting an RNP-incorporated cryogel proved that it is biocompatible, does not induce renal toxicity, aids wound healing, and induces better re-epithelialization than the control groups at the initial stages. Thus, RNP-incorporated cryogels containing bilayered skin substitutes are an advanced and novel alternative to commercial dermo-epidermal substitutes that lack anti-inflammatory or anti-scarring properties.

In-vitro evaluation of virulence markers and antifungal resistance of clinical Candida albicans strains isolated from Karachi, Pakistan

Candidiasis is a significant fungal infection with high mortality and morbidity rates worldwide. Candida albicans is the most dominant species responsible for causing different manifestations of candidiasis. Certain virulence traits as well as its resistance to antifungal drugs contribute to the pathogenesis of this yeast. This study was designed to determine the production of some virulence factors, such as biofilm formation and extracellular hydrolytic enzymes (esterase, coagulase, gelatinase, and catalase) by this fungus, as well as its antifungal resistance profile. A total of 304 clinical C. albicans isolates obtained from different clinical specimens were identified by a conventional diagnostic protocol. The antifungal susceptibility of C. albicans strains was determined by disk diffusion technique against commercially available antifungal disks, such as nystatin 50 μg, amphotericin B 100 unit, fluconazole 25 μg, itraconazole 10 μg, ketoconazole 10 μg, and voriconazole 1 μg. The assessment of biofilm formation was determined by the tube staining assay and spectrophotometry. Gelatinase, coagulase, catalase, and esterase enzyme production was also detected using standard techniques. A total of 66.1% (201/304) and 28.9% (88/304) of C. albicans strains were susceptible-dose dependent (SDD) to nystatin and itraconazole, respectively. Among the antifungal drugs, C. albicans strains showed high resistance to ketoconazole 24.7% (75/304); however, no statistically significant relationship between the clinical origin of C. albicans isolates and antifungal drug resistance pattern was detected. For virulence factors, the majority of the C. albicans strains actively produced biofilm and all hydrolytic enzymes. Biofilm formation was demonstrated by 88% (267/304) of the strains with a quantitative mean value 0.1762 (SD ± 0.08293). However, 100% (304/304) of isolates produced catalase enzyme, 69% (211/304) produced coagulase, 66% (197/304) produced gelatinase, and 52% (157/304) produced esterase enzyme. A significant relationship between the source of specimens and biofilm formation by C. albicans was observed; nevertheless, there was no significant relationship between different sources of C. albicans strains and the production of different enzymatic virulence factors. The study found that C. albicans strains have excellent potential to produce virulence markers and resistance to antifungals, which necessitates surveillance of these opportunistic pathogens to minimize the chances of severe invasive infections.

Isolation and Characterization of Streptococcus pyogenes from Iraqi Children with Pharyngotonsillitis

Background: Streptococcus pyogenes known as group A streptococci (GAS) is the main causative agent of pharyngotonsillitis in children younger than 12 years old. The infection appears mostly in winter and spring. Signs and symptoms of patients with a beta-hemolytic GAS infection, include tonsillar exudate, fever, painful anterior cervical adenopathy, and the lack of a cough. Penicillin and ampicillin are the preferred clinical therapy choice for GAS pharyngitis treatment. Objectives: Isolate and identify GAS in throat swabs among children suffering from acute pharyngotonsillitis to estimate the prevalence rate of bacterial isolates associated with age, sex, and months variation of GAS infection. Also, it is to determine the antibiotic sensitivity patterns such as penicillin, ampicillin, erythromycin, azithromycin, ofloxacin, clindamycin, and rifampicin, which are used for the treatment of GAS associated with the acute pharyngotonsillitis in children. Materials and Methods: Four hundred and ten throat swabs have been obtained from patients who were clinically diagnosed as having acute pharyngotonsillitis of age ranging from (1–12) years of both sexes were admitted to various hospitals and enrolled in a sequential manner from November 2021 to April 2022 in two Governorates (Baghdad and Babylon), Iraq. These throat swabs were exposed to the bacterial culturing, and some other tests. Streptococcus pyogenes isolates were identified depending on the colony properties, beta-hemolysis on sheep blood agar plate, Gram’s stain, catalase production test, in addition to a sensitivity to bacitracin and Pyrrolidinyl arylamidase test to confirm the identification of GAS. Results: The prevalence of identifying GAS isolates was 140 (34.1%) out of 410 samples. GAS strains can cause acute pharyngotonsillitis in children of all ages, but it most frequently occurred between 1 and 6 year age groups, and it was more in men 80 (57.1%) than in women 60 (42.9%). Likewise, it was found that GAS associated with acute pharyngotonsillitis with a high incidence in winter and in early spring, in which the peak of GAS infection has been seen in January (30.7%). On the other hand, some antibiotics were used to show their effect on these GAS isolates. The findings revealed that all isolates were sensitive (100%) to penicillin and ampicillin, and (83.6%) of isolates were sensitive to clindamycin, whereas some isolates shown a lesser degree of sensitivity (75% and 60%) to rifampicin and ofloxacin. However, only 49.3% of the isolates were sensitive to erythromycin, and (46.4%) were sensitive to azithromycin. Conclusion: GAS strains can cause acute pharyngotonsillitis in children of all ages, but it most frequently occurred in the age groups (1–6) year, and more predominant in men than in women. High percentage of infections with GAS have been noticed in winter and spring to reach its peak in January. Additionally, penicillin and ampicillin are preferred antibiotic for treatment, whereas in the most serious cases clindamycin was added to the treatment plan.

Resilience and bioresponse of two marine algae to petroleum fuel pollution

ABSTRACT Petroleum pollution can upset the ecological stability and health of a marine ecosystem. The physiological, biochemical and morphological responses of Nannochloropsis oculata and Porphyridium cruentum to three different petroleum fuels, kerosene, diesel and gasoline were examined. The effect of water soluble fractions (WSFs) of the three petroleum fuels was investigated at 0%, 25%, 50% and 100%. The growth response of both species was monitored optically every two days for 14 days using a 721 visible spectrophotometer. Chlorophyll a, morphology and antioxidant enzyme activity of the algae were examined using prescribed methods. In both algae, minimum growth was obtained with 100% WSF of the petroleum fuels. In N. oculata, there was growth stimulation and the maximum growth was obtained at different concentrations (25% and 50%) depending on the test fuels. The maximum growth of P. cruentum was obtained at 10% WSF in all the fuels. ANOVA (p < 0.05) showed significant differences in algal growth with changes in concentration of the test fuels. Unpaired t-tests showed that in all the fuels, there was a significant difference (p < 0.05) between the growth of N. oculata and P. cruentum. N. oculata showed more tolerance to petroleum fuel pollution than P. cruentum. Morphological studies showed that petroleum fuel pollution altered the size of N. oculata and caused severe cell clumping in P. cruentum. Antioxidant concentration assessment showed that whereas N. oculata produced high levels of superoxide dismutase, catalase and peroxidase, P. cruentum produced high levels of superoxide dismutase but was less efficient in catalase and peroxidase production. Clumping and inefficiency in antioxidant production affect the physiological and biochemical response of algae. This study showed that the severity of petroleum fuel pollution is reflected in physiological, morphological, and biochemical responses of the test algae. This research provides baseline information that can be used for the evaluation of the effect of petroleum fuel pollution in marine environment and policy making.

Concurrent Dietary Incorporation of Bentonite Clay Reduces Aflatoxin Induced Health Effects In White Pekin Ducks

An experiment was carried out to assess the efficacy bentonite clay supplementation to the diet of white pekin ducks, experimentally fed with aflatoxin B1 contaminated diet (96 ppb) on production performance, and biochemical parameters including oxidative stress indices. The experimental birds (n=72) were provided with standard duck feed and ad libitum water. The grower white pekin ducks, aged 9 weeks, were randomly divided into six groups containing twelve birds in each group. The birds of group I served as healthy controls and was fed with basal diet without addition of toxin or bentonite clay. The birds of group II were provided with a diet with toxin level of 48 µg/kg of feed. The grower ducklings of group III to VI were fed with a diet containing 96 µg of toxin/kg of feed. The experimental feed was provided from 9th week of age (grower stage) for a period of 6 weeks. The birds of group IV, V and VI were provided with feed containing 96 µg aflatoxin /kg of feed along with bentonite clay the dose rate of 1, 2 or 3g of clay/ kg of feed, respectively. The birds fed with aflatoxin-treated diet showed significant (P&lt;0.05) decrease in body weight gain by 4th week of experiment in group II and III. However, the body weight was significantly (P&lt;0.05) higher in bentonite clay supplemented group IV, V, and VI, as compared to toxin-exposed positive group II and III. Feed Conversion Ratio (FCR) increased significantly in Group II and III by 4th week. At the end of 6th week, group II and III showed significantly higher FCR. Significantly decreased serum triglyceride level and increased cholesterol level was recorded in group II and III in comparison to all other groups on 4th week. There was significant decrease in creatinine level in group IV, V, and VI, compared to group II and III on completion of 4th week of the experiment. The activity of GGT increased significantly in all aflatoxin exposed groups. The feeding of aflatoxin contaminated feed increased the erythrocytic malonaldehyde (MDA) production and activity of superoxide dismutase and catalase. It is concluded from the experiment that bentonite clay supplementation in the diet at the dose rate of 3g/ kg of feed reduced the toxic effects of aflatoxin on production performance and oxidative stress in white pekin ducks.

Interactive effects of Pseudomonas putida and salicylic acid for mitigating drought tolerance in canola (Brassica napus L.)

This research was designed to analyze the interactive effects of Pseudomonas putida and salicylic acid on the growth of canola in stress and non-stress conditions. Salicylic acid is a phenolic derivative, that has a direct involvement in various plant stages like growth, and inflorescence. While Pseudomonas putida is a drought-tolerant strain having plant growth-promoting characteristics like phosphate solubilization, indole acetic acid, and catalase production. Combined application of Pseudomonas putida and salicylic acid has the ability to develop stress tolerance in plants and also improve growth of plants. They have significant (p < 0.05) effects on germination and morphological, physiological, and biochemical parameters. The plants that received the co-application of Pseudomonas putida and salicylic acid gave more significant results than their alone application. They showed enhanced germination percentage, germination index, promptness index and, seedling vigor index by 19%, 18%, 34% and, 27%, respectively. There was a substantial increase of 25%, 27%, and 39% in shoot length, root length, and leaf area, respectively. The synergistic effect of both treatments has caused a 14% and 12% increase in the Canola plants' relative water content and membrane stability index respectively. A substantial increase of 18% in proline content was observed by the inoculation of Pseudomonas putida, whereas proline content was increased by 28% by the exogenous application of salicylic acid. The content of flavonoids (39%) and phenol (40%) was significantly increased by the co-application. The increase in superoxide dismutase (46%), ascorbate peroxidase (43%), and glutathione (19%) were also significant. The present research demonstrated that the combined application of Pseudomonas putida and salicylic acid induces drought tolerance in canola and significantly improves its growth.

Characterization of Streptomyces sp. KB1 and its cultural optimization for bioactive compounds production.

Bioactive compounds (BCs) from natural resources have been extensively studied because of their use as models in the development of novel and important medical and biopreservative agents. One important source of BCs is microorganisms, particularly terrestrial bacteria of the order Actinomycetales. We characterized Streptomyces sp. KB1 by observing its morphology, physiology, and growth on different media using biochemical tests, optimizing cultural conditions by changing one independent variable at a time. Streptomyces sp. KB1 (TISTR 2304) is a gram-positive and long filamentous bacteria that forms straight to flexuous (rectiflexibile) chains of globose-shaped and smooth-surfaced spores. It can grow under aerobic condition s only at a temperature range of 25-37°C and initial pH range of 5-10 in the presence of sodium chloride 4% (w/v). Therefore, it is considered an obligate aerobe, mesophilic, neutralophilic, and moderately halophilic bacteria. The isolate grew well on peptone-yeast extract iron, Luria Bertani (LB), and a half-formula of LB (LB/2), but could not grow on MacConkey agar. It utilized fructose, mannose, glucose, and lactose as its carbon source along with acid production and showed positive reactions to casein hydrolysis, gelatin liquefaction, nitrate reduction, urease, and catalase production. Streptomyces sp. KB1 (TISTR 2304) could produce the maximum number of BCs when 1% of its starter was cultivated in a 1,000 ml baffled flask containing 200 ml of LB/2 broth with its initial pH adjusted to 7 with no supplemental carbon source, nitrogen source, NaCl, or trace element at 30°C, shaken at 200 rpm in an incubator for 4 days.