Showed Protease Activity Research Articles

IAA-producing plant growth promoting rhizobacteria from Ceanothus velutinus enhance cutting propagation efficiency and Arabidopsis biomass.

Climate-induced drought impacts plant growth and development. Recurring droughts increase the demand for water for food production and landscaping. Native plants in the Intermountain West region of the US are of keen interest in low water use landscaping as they are acclimatized to dry and cold environments. These native plants do very well at their native locations but are difficult to propagate in landscape. One of the possible reasons is the lack of associated microbiome in the landscaping. Microbiome in the soil contributes to soil health and impacts plant growth and development. Here, we used the bulk soil from the native plant Ceanothus velutinus (snowbrush ceanothus) as inoculant to enhance its propagation. Snowbrush ceanothus is an ornamental plant for low-water landscaping that is hard to propagate asexually. Using 50% native bulk soil as inoculant in the potting mix significantly improved the survival rate of the cuttings compared to no-treated cuttings. Twenty-four plant growth-promoting rhizobacteria (PGPR) producing indole acetic acid (IAA) were isolated from the rhizosphere and roots of the survived snowbrush. Seventeen isolates had more than 10µg/mL of IAA were shortlisted and tested for seven different plant growth-promoting (PGP) traits; 76% showed nitrogen-fixing ability on Norris Glucose Nitrogen free media,70% showed phosphate solubilization activity, 76% showed siderophore production, 36% showed protease activity, 94% showed ACC deaminase activity on DF-ACC media, 76% produced catalase and all of isolates produced ammonia. Eight of seventeen isolates, CK-6, CK-22, CK-41, CK-44, CK-47, CK-50, CK-53, and CK-55, showed an increase in shoot biomass in Arabidopsis thaliana. Seven out of eight isolates were identified as Pseudomonas, except CK-55, identified as Sphingobium based on 16S rRNA gene sequencing. The shortlisted isolates are being tested on different grain and vegetable crops to mitigate drought stress and promote plant growth.

Lipase and Protease Production Ability of Multi-drug Resistant Bacteria Worsens the Outcomes of Wound Infections.

Surgical site infections are one of the major clinical problems in surgical departments that cost hundreds of millions of dollars to healthcare systems around the world. The study aimed to address the pressing issue of surgical site infections, which pose significant clinical and financial burdens on healthcare systems globally. Recognizing the substantial costs incurred due to these infections, the research has focused on understanding the role of lipase and protease production by multi-drug resistant bacteria isolated from surgical wounds in the development of post-surgical wound infections. For these purposes, 153 pus specimens were collected from patients with severe post-surgical wound infections having prolonged hospital stays. The specimens were inoculated on appropriate culture media. Gram staining and biochemical tests were used for the identification of bacterial growth on suitable culture media after 24 hours of incubation. The isolated pathogens were then applied for lipase and protease, key enzymes that could contribute to wound development, on tributyrin and skimmed milk agar, respectively. Following the CSLI guidelines, the Kirby-Bauer disc diffusion method was used to assess antibiotic susceptibility patterns. The results revealed that a significant proportion of the samples (127 out of 153) showed bacterial growth of Gram-negative (n = 66) and Gram-positive (n = 61) bacteria. In total, isolated 37 subjects were declared MDR due to their resistance to three or more than three antimicrobial agents. The most prevalent bacteria were Staphylococcus aureus (29.13%), followed by S. epidermidis (18.89%), Klebsiella pneumoniae (18.89%), Escherichia coli (14.96%), Pseudomonas aeruginosa (10.23%), and Proteus mirabilis (7.87%). Moreover, a considerable number of these bacteria exhibited lipase and protease activity with 70 bacterial strains as lipase positive on tributyrin agar, whereas 74 bacteria showed protease activity on skimmed milk agar with P. aeruginosa as the highest lipase (69.23%) and protease (76.92%) producer, followed by S. aureus (lipase 62.16% and protease 70.27%). The antimicrobial resistance was evaluated among enzyme producers and non-producers and it was found that the lipase and protease-producing bacteria revealed higher resistance to selected antibiotics than non-producers. Notably, fosfomycin and carbapenem were identified as effective antibiotics against the isolated bacterial strains. However, gram-positive bacteria displayed high resistance to lincomycin and clindamycin, while gram-negative bacteria were more resistant to cefuroxime and gentamicin. In conclusion, the findings suggest that lipases and proteases produced by bacteria could contribute to drug resistance and act as virulence factors in the development of surgical site infections. Understanding the role of these enzymes may inform strategies for preventing and managing post-surgical wound infections more effectively.

Enzyme characterization of lactic acid bacteria isolated from duck excreta.

The production of lignocellulosic biomass waste in the agricultural sector of Indonesia is quite high annually. Utilization of lignocellulosic biomass waste through fermentation technology can be used as feed and biofuel. Fermentation technology requires the involvement of micro-organisms such as bacteria (lactic acid bacteria or LAB). LABs can be isolated from various sources, such as duck excreta. However, there have not been many reports of LAB from duck excreta. The present study aimed to characterize LAB enzymes isolated from duck excreta and obtain LAB enzymes with superior fermentation properties. A total of 11 LAB cultures obtained from duck excreta in Yogyakarta, Indonesia, were tested. Enzyme characterization of each LAB was performed using the API ZYM kit (BioMérieux, Marcy-I'Etoile, France). The bacterial cell suspension was dropped onto the API ZYM™ cupule using a pipette and incubated for 4 h at 37°C. After incubation, ZYM A and ZYM B were dripped onto the API ZYM cupule, and color changes were observed for approximately 10 s under a strong light source. Esterase activity was moderate for all LABs. The activity of α-chymotrypsin, β-glucuronidase, α-fucosidase, and α-mannosidase was not observed in a total of 10 LAB. The phosphohydrolase and amino peptidase enzyme activity of seven LABs was strong. Only six LAB samples showed protease activity. The glycosyl hydrolase (GH) activity was observed in a total of 8 LAB, while the activity of 2 LAB was strong (Lactococcus lactis subsp. lactis K5 and Lactobacillus brevis M4A). A total of 2 LABs have superior properties. L. lactis subsp. lactis K5 and L. brevis M4A have a high potential to be used in fermentation. They have the potential for further research, such as their effectiveness in fermentation, lignocellulose hydrolysis, feed additives, molecular characterization to detect specific enzymes, and their specific activities.

Novel Strain Leuconostoc lactis DMLL10 from Traditional Korean Fermented Kimchi as a Starter Candidate for Fermented Foods.

Leuconostoc lactis strain DMLL10 was isolated from kimchi, a fermented vegetable, as a starter candidate through safety and technological assessments. Strain DMLL10 was susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, kanamycin, streptomycin, and tetracycline. It did not show any hemolytic activity. Regarding its phenotypic results related to its safety properties, genomic analysis revealed that strain DMLL10 did not encode for any toxin genes such as hemolysin found in the same genus. It did not acquire antibiotic resistance genes either. Strain DMLL10 showed protease activity on agar containing NaCl up to 3%. The genome of DMLL10 encoded for protease genes and possessed genes associated with hetero- and homo-lactic fermentative pathways for lactate production. Finally, strain DMLL10 showed antibacterial activity against seven common foodborne pathogens, although bacteriocin genes were not identified from its genome. These results indicates that strain DMLL10 is a novel starter candidate with safety, enzyme activity, and bacteriocin activity. The complete genomic sequence of DMLL10 will contribute to our understanding of the genetic basis of probiotic properties and allow for assessment of the effectiveness of this strain as a starter or probiotic for use in the food industry.

Novel Starter Strain Enterococcus faecium DMEA09 from Traditional Korean Fermented Meju.

The Enterococcus faecium strain DMEA09 was previously isolated from traditional Korean fermented meju. The objective of the current study was to investigate the traits of E. faecium strain DMEA09 as a starter candidate, focusing on its safety and technological properties. Regarding its safety, the DMEA09 strain was found to be sensitive to nine antibiotics (ampicillin, chloramphenicol, erythromycin, gentamicin, kanamycin, streptomycin, tetracycline, tylosin, and vancomycin) by showing lower minimum inhibitory concentrations (MICs) than the cut-off values suggested by the European Union Food Safety Authority for these nine antibiotics. However, its MIC value for clindamycin was twice as high as the cut-off value. A genomic analysis revealed that strain DMEA09 did not encode the acquired antibiotic resistance genes, including those for clindamycin. The DMEA09 strain did not show hemolysis as a result of analyzing α- and β-hemolysis. It did not form biofilm either. A genomic analysis revealed that strain DMEA09 did not encode for any virulence factors including hemolysin. Most importantly, multilocus sequence typing revealed that the clonal group of strain DMEA09 was distinguished from clinical isolates. Regarding its technological properties, strain DMEA09 could grow in the presence of 6% salt. It showed protease activity when the salt concentration was 3%. It did not exhibit lipase activity. Its genome possessed 37 putative protease genes and salt-tolerance genes for survivability under salt conditions. Consequently, strain DMEA09 shows safe and technological properties as a new starter candidate. This was confirmed by genome analysis.

Characteristics of Lactic Acid bacteria isolated from traditional fermented fish

Abstract. Novia R, Ardiningsih P, Adhityawarman, Sarwiyati. 2022. Characteristics of Lactic Acid bacteria isolated from traditional fermented fish. Biodiversitas 23: 5662-5669. Lactic acid bacteria (LAB) are commonly involved in most food fermentation and contribute to the process’s quality and safety. The study investigates the characteristics of LAB isolated from buduk, pekasam, and pekasam ale-ale. Twelve colonies each sample were isolated and identified based on morphology and biochemical test. The pekasam ale-ale isolates were identified as Pediococcus sp. strain A1 and Pediococcus sp. strain A3; Enterococcus sp. strain A2 and Enterococcus sp. strain A4. The LAB in buduk were identified as Streptococcus sp. strain B1, Pediococcus sp. strain B2 and Pediococcus sp. strain B4, Enterococcus sp. strain B3. The pekasam isolates were identified as Pediococcus sp. strain P1, Streptococcus sp. strain P2 and Streptococcus sp. strain P4, Lactobacillus sp. strain P3. The LAB showed antimicrobial activities while Lactobacillus sp. strain P3 and Streptococcus sp. strain P4 could grow at pH 1. Two LAB including Enterococcus sp. strain A2 and Pediococcus sp. strain P1 showed amylase activity while Pediococcus sp. strain A3, Streptococcus sp. strain B1, Pediococcus sp. strain B2, Enterococcus sp. strain B3 showed protease activity. All LAB produced organic acids with varying concentrations at different incubation times. Furthermore, those isolated from various fish fermentations showed different genera and characteristics. Lactobacillus sp. strain P3 was the best to initiate food fermentation and a probiotic candidate based on their characteristics.

A serralysin-like protein of Candidatus Liberibacter asiaticus modulates components of the bacterial extracellular matrix.

Huanglongbing (HLB), the current major threat for Citrus species, is caused by intracellular alphaproteobacteria of the genus Candidatus Liberibacter (CaL), with CaL asiaticus (CLas) being the most prevalent species. This bacterium inhabits phloem cells and is transmitted by the psyllid Diaphorina citri. A gene encoding a putative serralysin-like metalloprotease (CLIBASIA_01345) was identified in the CLas genome. The expression levels of this gene were found to be higher in citrus leaves than in psyllids, suggesting a function for this protease in adaptation to the plant environment. Here, we study the putative role of CLas-serralysin (Las1345) as virulence factor. We first assayed whether Las1345 could be secreted by two different surrogate bacteria, Rhizobium leguminosarum bv. viciae A34 (A34) and Serratia marcescens. The protein was detected only in the cellular fraction of A34 and S. marcescens expressing Las1345, and increased protease activity of those bacteria by 2.55 and 4.25-fold, respectively. In contrast, Las1345 expressed in Nicotiana benthamiana leaves did not show protease activity nor alterations in the cell membrane, suggesting that Las1345 do not function as a protease in the plant cell. Las1345 expression negatively regulated cell motility, exopolysaccharide production, and biofilm formation in Xanthomonas campestris pv. campestris (Xcc). This bacterial phenotype was correlated with reduced growth and survival on leaf surfaces as well as reduced disease symptoms in N. benthamiana and Arabidopsis. These results support a model where Las1345 could modify extracellular components to adapt bacterial shape and appendages to the phloem environment, thus contributing to virulence.

Occurrence, antimicrobial resistance, virulence, and biofilm formation capacity of Vibrio spp. and Aeromonas spp. isolated from raw seafood marketed in Bangkok, Thailand.

Background and Aim:Bacteria of the genera Vibrio and Aeromonas cause seafood-borne zoonoses, which may have a significant impact on food safety, economy, and public health worldwide. The presence of drug-resistant and biofilm-forming phenotypes in the food chain increases the risk for consumers. This study aimed to investigate the characteristics, virulence, biofilm production, and dissemination of antimicrobial-resistant pathogens isolated from seafood markets in Bangkok, Thailand.Materials and Methods:A total of 120 retail seafood samples were collected from 10 local markets in Bangkok and peripheral areas. All samples were cultured and the Vibrio and Aeromonas genera were isolated using selective agar and biochemical tests based on standard protocols (ISO 21872-1: 2017). The antibiotic susceptibility test was conducted using the disk diffusion method. The presence of hemolysis and protease production was also investigated. Polymerase chain reaction (PCR) was used to determine the presence of the hlyA gene. Furthermore, biofilm formation was characterized by microtiter plate assay and scanning electron microscopy.Results:The bacterial identification test revealed that 35/57 (61.4%) belonged to the Vibrio genus and 22/57 (38.6%) to the Aeromonas genus. The Kirby–Bauer test demonstrated that 61.4% of the isolates were resistant to at least one antibiotic and 45.61% had a high multiple antibiotic resistance index (≥0.2). PCR analysis indicated that 75.44% of the bacteria harbored the hlyA gene. Among them, 63.16% exhibited the hemolysis phenotype and 8.77% showed protease activity. The biofilm formation assay demonstrated that approximately 56.14% of all the isolates had the potential to produce biofilms. The moderate biofilm production was the predominant phenotype.Conclusion:The results of this study provide evidence of the multiple drug resistance phenotype and biofilm formation capacity of Vibrio and Aeromonas species contaminating raw seafood. Effective control measures and active surveillance of foodborne zoonoses are crucial for food safety and to decrease the occurrence of diseases associated with seafood consumption.

The safety and technological properties of Bacillus velezensis DMB06 used as a starter candidate were evaluated by genome analysis

Screening of good starter candidates for fermented food is continuously required. Accordingly, safety and functional evaluation were performed for 171 Bacillus velezensis strains isolated from fermented soybeans. All the strains were susceptible to ampicillin, chloramphenicol, clindamycin, erythromycin, gentamicin, and vancomycin; however, one and 135 strains showed resistance to streptomycin and tetracycline, respectively. No toxin-related genes were identified in any of the strains. All the strains grew on medium supplemented with 10% NaCl, and some strains grew weakly at ≥15% (w/w) NaCl. All the strains bar one showed protease activity in 6% NaCl; 32.7% of the strains showed lipase activity. On the basis of these assessments, B. velezensis strain DMB06 was selected as the best starter candidate because of its high protease and lipase activities. Its whole genome was sequenced, providing genetic information to support its phenotypic salt tolerance, protease and lipase activities, antibiotic susceptibility, and the absence of toxin and aminoglycoside production. Our results suggest that B. velezensis DMB06 can be safely applied as a starter candidate in the food industry.

Evaluation of the milk clotting potential and characterization of proteases from Aspergillus sp. and Pleurotus albidus

The study evaluated the production of proteases in solid-state fermentation using wheat bran as a substrate. The best producing isolates were used to obtain crude extract which was evaluated for optimal pH and temperature, thermostability, effect of salts and activity against inhibitors. The studied fungi were Aspergillus sp. 125, Fusarium sp. 132, Fusarium sp. 206, Pleurotus albidus 018 and Pleurotus pulmonarius CCB20. The isolates with better results (Aspergillus sp. and P. albidus), showed protease activity with an optimum pH of 7.0, and an optimum temperature of 50ºC with good thermostability between 40 and 50ºC. As for salts, the protease activity was inhibited in the presence of ZnSO4, and the activity of the proteases from the crude Aspergillus extract, strongly inhibited by PMSF, indicating the presence of a fraction of serine protease in the extract. The extracts of the two selected isolates showed considerable inhibition by EDTA. The milk clotting activity was 240 U mL-1 for the Aspergillus extract and 153 U mL-1 for the crude P. albidus extract. Proteases are important enzymes widely used in the food industry, including cheese. The data suggest that these fungi have the potential to produce these enzymes for usage in cheese making

Potential for resistance to freezing by non-virulent bacteria isolated from Antarctica.

Industrial sectors are searching for new compounds to improve the preservation of food and blood, human tissues, and fuels used at low temperatures. Antarctic microorganisms have mechanisms to overcome injuries caused by low temperatures, making them sources of compounds with antifreeze activity. However, it is mandatory that such compounds do not pose a risk to human health. The present study evaluated the potential of Antarctic bacteria to resist freezing, produce virulence factors, their tolerance to physiological pHs/temperature and resistance to antibiotics. Sixty-five isolates were tested for antifreeze compound production, among which, 31 grew after the test. Of these, 3 strains of Arthrobacter sp. (356, 358 and 443), one Psychromonas arctica (ESH238) and one unidentified strain (363) showed positive results for hemolytic activity. Psychrobacter sp. 456 showed proteinase activity. None of the isolates showed resistance to the antibiotics. All isolates were able to grow in one of the three pHs (4, 7 and 8) and/or temperature (36, 38 and 40 ºC). Antarctic bacterial present potential for the production of antifreeze compounds and may be considered safe in industrial processes. The characterization of the genes responsible for virulence factors should be carried out to reinforce the potential applicability of such bacteria.

Promoting effect of the recombinant resuscitation promoting factors-2 of Rhodococcus erythropolis on petroleum degradation and cultivable bacterial diversities of the oil-contaminated soils.

Resuscitation-promoting factors (Rpfs) belong to peptidoglycan hydrolases, which participate in recovery of dormant cells and promoting bacteria growth. In this study, the resuscitation promoting factor rpf2 gene of Rhodococcus erythropolis KB1 was expressed in Escherichia coli and purified by Ni2+ affinity chromatography. The purified recombinant fusion protein Rpf2 showed a closely 50 kDa band on sodium dodecyl sulphate polyacrylamide gel electrophoresis. The protein showed muralytic activity, with a specific activity of 1503 ± 123 U mg-1 when determined with 4-methylumbelliferyl-β-d-N, N',N″-triacetotri-ylchitoside as substrate. It also showed protease activity when measured with azocasein as substrate, with a specific activity of 1528 ± 411 U mg-1 . The addition of the recombinant Rpf2 protein significantly increased petroleum degradation efficiency of the indigenous micro-organisms and the petroleum degradation rates increased from 30·86 to 43·45%, 45·20 and 49·23% in the treatment groups. The recombinant protein also increased the petroleum-degrading bacterial diversities enriched from the contaminated soils. The cultivable bacterial flora of the treatment groups supplemented with different concentrations of Rpf2 increased from 82 genera in 9 phyla to 116 genera in 16 phyla and 138 genera in 16 phyla respectively. Thirteen extra petroleum-degrading bacteria strains were isolated from the petroleum-contaminated soils in the groups containing the recombinant Rpf2.

Candiduria—Study of Virulence Factors and Its Antifungal Susceptibility Pattern in Tertiary Care Hospital

Background The increased incidence of candiduria in hospitalized patients is due to the use of indwelling devices, long-term antibiotics, parenteral nutrition, and immunocompromised status of the patient. In this study, an attempt was made to speciate, characterize, and determine the antifungal susceptibility pattern of Candida isolated from urinary tract infections (UTIs). Materials and Methods A total of 70 Candida isolates were obtained from urine samples. The isolated Candida species were studied for the production of virulence factors like phospholipase, protease activities, hemolysin, and biofilm production. Antifungal susceptibility testing of the isolated yeasts was done using Mueller-Hinton agar supplemented with 0.5 mg/mL methylene blue by E-test method for amphotericin B, fluconazole, caspofungin, and voriconazole. Results Out of 70 isolates, Candida tropicalis was the most frequently isolated species (65.7%), followed by Candida albicans (14.3%), Candida glabrata (7.1%), Candida krusei (5.7%), Candida parapsilosis (4.3%), and Candida dubliniensis (2.9%). A total of 37.1% were biofilm producers, 62.9% showed proteinase activity, 38.6% were phospholipase positive, and 58.6% isolates showed hemolytic activity. Antifungal susceptibility profile of Candida species showed 38.6, 25.7, 15.7, and 12.9% resistance to amphotericin B, fluconazole, caspofungin, and voriconazole, respectively. Conclusion A rising trend in isolation of non-albicans Candida from urinary isolates was noticed, which was statistically significant when comparing catheterized and noncatheterized urinary isolates from our study. However, there was no statistically significant difference when different virulence factor expressions were compared among Candida spp. isolated from catheterized and noncatheterized urinary samples. Due to this rise in non-albicans Candida species causing UTI that are intrinsically resistant to certain antifungal agents like azoles and increasing incidence of antifungal resistance, it is essential to monitor the antifungal susceptibility profile of Candida species causing candiduria.

Safety Evaluation of Yeasts With Probiotic Potential.

This work has evaluated the safety aspects of 20 yeast strains, isolated from food environments, selected in previous works due to their probiotic potential. Among the different strains, there are Saccharomyces and non-Saccharomyces yeasts. Before safety evaluation, differentiation of Saccharomyces cerevisiae strains was done by PCR amplification of inter-δ region with pairs of primers δ2-12 and δ12-21, which showed that they were all different from each other and also had different profiles to Saccharomyces boulardii (the only commercial probiotic yeast). The non-Saccharomyces ones were already known. The evaluation tests carried out were antibiotic and antifungal resistance, production of biogenic amines, deconjugation activity of bile salts, and different enzymatic activities: coagulase, deoxyribonuclease, hemolysin, proteolytic, and phospholipase. None of the studied strains demonstrated coagulase, hemolytic or DNase capacity (clear virulence factors), although all of them showed protease activity, some showed phospholipase activity, and half of the yeasts were capable of conjugating bile salts. Regarding antimicrobial compounds, all were resistant to antibiotics but showed sensitivity to the antimycotics used. Nevertheless, only one strain of Hanseniaspora osmophila was excluded for use in the food industry, due to its high production of tyramine.

Elevated Dipeptidyl Peptidase IV (DPP-IV) Activity in Plasma from Patients with Various Lysosomal Diseases.

Increased activity of dipeptidyl peptidase IV (DPP-IV) was reported earlier in patients with different types of mucopolysaccharidoses. DPP-IV (also known as CD26 lymphocyte T surface antigen) is a transmembrane protein showing protease activity. This enzyme displays various functions in the organism and plays an important role in multiple processes like glucose metabolism, nociception, cell-adhesion, psychoneuroendocrine regulation, immune response and cardiovascular adaptation. In order to evaluate DPP-IV in lysosomal storage diseases (LSD), we examined its activity in plasma samples from 307 patients affected with 24 different LSDs and in 75 control persons. Our results revealed elevated DPP-IV activity especially in individuals affected with mucolipidosis II/III, alpha-mannosidosis, and mucopolysaccharidoses types III, II, and I (p < 0.05). In other LSDs the DPP-IV activity was still significantly increased, but to a lesser extent. In patients with Gaucher disease, ceroid lipofuscinosis type 1 (CLN1), Niemann–Pick disease type C and A, Krabbe and Pompe diseases, gangliosidosis GM2 and metachromatic leukodystrophy discreet or no changes in DPP-IV activity were observed. DPP-IV may serve as a first-tier diagnostic procedure or additional biochemical analysis in recognizing patients with some LSDs. DPP-IV may become an object of basic research for a better understanding of LSDs.

Plant growth promoting and antifungal asset of indigenous rhizobacteria secluded from saffron (Crocus sativus L.) rhizosphere

Saffron (Crocus sativus L.) is an important plant in medicine. The Kashmir Valley (J&K, India) is one of the world's largest and finest saffron producing regions. However, over the past decade, there has been a strong declining trend in saffron production in this area. Plant Growth Promoting Rhizobacteria (PGPR) are free living soil bacteria that have ability to colonize the surfaces of the roots and ability to boost plant growth and development either directly or indirectly. Using the efficient PGPR as a bio-inoculant is another sustainable agricultural practice to improve soil health, grain yield quality, and biodiversity conservation. In the present study, a total of 13 bacterial strains were isolated from rhizospheric soil of saffron during the flowering stage of the tubers and were evaluated for various plant growth promoting characteristics under in vitro conditions such as the solubilization of phosphate, production of indole acetic acid, siderophore, hydrocyanic acid, and ammonia production and antagonism by dual culture test against Sclerotium rolfsii and Fusarium oxysporum. All the isolates were further tested for the production of hydrolytic enzymes such as protease, lipase, amylase, cellulase, and chitinase. The maximum proportions of bacterial isolates were gram-negative bacilli. About 77% of the bacterial isolates showed IAA production, 46% exhibited phosphate solubilization, 46% siderophore, 61% HCN, 100% ammonia production, 69% isolates showed protease activity, 62% lipase, 46% amylase, 85% cellulase, and 39% showed chitinase activity. Three isolates viz., AIS-3, AIS-8 and AIS-10 were found to have the most plant growth properties and effectively control the growth of Sclerotium rolfsii and Fusarium oxysporum. The bacterial isolates were identified as Brevibacterium frigoritolerans (AIS-3), Alcaligenes faecalis subsp. Phenolicus (AIS-8) and Bacillus aryabhattai (AIS-10) respectively by 16S rRNA sequence analysis. Therefore, these isolated rhizobacterial strains could be a promising source of plant growth stimulants to increase cormlets growth and increase saffron production.

Invasive Factors Recognition in Aspergillus Section Nigri Isolates from Patient and Environmental Samples in the Centre Region, Cameroon

Background: Aspergillus section Nigri species are invasive opportunistic pathogens, seen in individuals with various immune disorders. The invasive capacity involves the production of varieties of enzymes such as lipases, phospholipase, proteases and hyaluronidase. The determination of proteinase, phospholipase, esterase and biofilm production in patient and environmental isolates approve the pathogenic strength of the species.&#x0D; Aims: To evaluate the invasive capacity of Aspergillus section Nigri isolates from patients and environmental samples.&#x0D; Methods: Our study is cross sectional and experimental, performed at the outpatient clinic of the otorhinolaryngology department of Central and University teaching hospital during a period of 12 months from March 2018 to February 2019. To determine the invasive capacity of Aspergillus section Nigri species, 400 samples were evaluated in the study (that is; 250 from patients and 150 samples from environment). Patient samples and hospital environment samples were evaluated by standard phenotypic methods for detecting of Proteinase, phospolipase, esterase and biofilm. The variables were statistically analyzed using Chi-square test of independent and SPSS (Version 16.0).&#x0D; Results: The isolates recovered from the patient sample shows maximum invasive capacity as compared to the environmental isolates, that is for 44 isolates; 42 isolates showed proteinase activity and biofilm production, followed by phospholipase activity 36, and then esterase 32.The isolates recovered from the hospital environment also showed the production of the various invasive factors, that is for 16 isolates; 15 isolates showed biofilm production, followed by proteinase activity 6, phospholipase 5 and esterase 4.The disparities of the invasive capacity in patient and environment isolates virulence were statistically significant for proteinase, phospholipase and esterase ( that is; p-value &lt;0.05). Majority the isolates recovered from patients and the environment were potential producers of biofilm.&#x0D; Conclusion: The isolates recovered from patients sample showed high invasive capacity as compare to the isolates recovered from the environment. This highlights the implications of phospholipase enzyme, proteinase enzyme, esterase enzyme and biofilm used by Aspergillus section Nigri isolates as means of survival in the host system.

Isolation and Characterization of Microbial Strains with Hydrolytic Enzyme Profile from Clay Minerals

Sulhee Lee , Eui-Sang Cho , Young-Do Nam , So-Lim Park , Seong-Il Lim , Dong-Ho Seo , Jae-Hwan Kim and Myung-Ji Seo . Microbiol. Biotechnol. Lett. 2020;48:64-71. https://doi.org/10.4014/mbl.1910.10016

Potential Thermotolerant Lactobacilli Isolated from Chicken Gastrointestinal Tract for Probiotic Use in Poultry Feeds

This research was carried out to isolate and identify thermotolerant lactobacilli from broiler chicken gastrointestinal tract from Dhaka, Bangladesh. Twenty five thermotolerant Lactobacillus strains were isolated and identified as Lactobacillus species based on cultural characteristics, biochemical tests, and sugar fermentation. The probiotic are a live microbial feed supplements which positively affects the health of the host animal by improving its intestinal balance.The results showed only four among twenty five isolates were highly responded to probiotic criteria such as low pH tolerance (2.5), bile salt tolerance (2%) and sodium chloride salt tolerance (5%) in vitro, and were identified strains as Lactobacillus plantarum img-02, Lactobacillus plantarum img-08, Lactobacillus plantarum img-10 and Lactobacillus acidophilus img-14 according to Bergey’s Manual of Systematic Bacteriology. Four isolates grow enough at 45°C and two isolates (Lactobacillus plantarum img-10 and Lactobacillus acidophilus img-14) heat stable at 60°C for 30 min. All the strains were showed protease activity on skim milk agar. These strains were resistance to commercial antibiotic ciprofloxacin, gentamycin, imipenem and penicillin G but sensitive to ampicillin, doxycycline, erythromycin and tetracycline; also have antimicrobial activity against common pathogen such as ATCC of Salmonella enteritidis, Staphylococcus aureus, Listeria monocytogenes, Shigella flexneri, Bacillus cereus, Klebsiella pneumonia, Escherichia coli (environmental isolates), Aspergillus flavus and Candida albicans. This study concludes that these isolates may be used as potential candidate as probiotic poultry feed.&#x0D; Bangladesh J Microbiol, Volume 36 Number 2 December 2019, pp 63-68

Bioprospecting Psychrotrophic Bacteria for Serine-Type Proteases from the Cold Areas of Western Himalayas.

The aim of present study was to analyze the prevalence of protease diversity among psychrotrophic bacteria in Lahaul and Spiti of the Western Himalayas. A total of 459 bacteria were screened and protease activity was observed in 150 isolates at 5°C. Furthermore, 55 isolates showed protease activity up to pH 10 at 5°C. Based on the hydrolytic zone, 22 isolates were selected for protease quantification. The protease activity varied from 58-377UmL-1 at 10°C, 49-396UmL-1 at 28°C and 31-407UmL-1 at 37°C. Similarly, protease activity ranged from 36-353UmL-1 at pH 7, 40-306UmL-1 at pH 9 and 33-304UmL-1 at pH 10. The isolates were identified based on 16S rRNA gene sequencing and showed phylogenetic relationship to Arthrobacter belonging to the class Actinobacteria, Bacillus, Exiguobacterium, Paenibacillus, and Planomicrobium to Bacilli, and Pseudomonas, Serratia, and Stenotrophomonas to Gammaproteobacteria. Zymogram analysis revealed variations in protease isoforms ranging from 20 to 250kDa which were strongly inhibited in the presence of phenylmethylsulfonyl fluoride, thus indicated serine-type nature. The extensive number of serine proteases among these bacteria was confirmed by annotating genomes of the reported genera for prevalence of protease isoforms. The properties of proteases including low-temperature activity with alkaline stability and detergent compatibility suggested their suitability as bio-additives in laundry.