Dilution Technique Research Articles

Nitrogen mineralization and immobilization in surface sediments of coastal reclaimed aquaculture ecosystems

Sediment nitrogen (N) mineralization and immobilization are two crucial processes driven by microorganisms, which may play significant roles in the regulation of water quality in aquaculture ecosystems. However, limited information is available about the quantitative importance of sedimentary N mineralization and immobilization in coastal aquaculture systems. Here, a combination of incubation experiments with a 15N isotope dilution technique were employed, aiming to quantify N mineralization and immobilization processes in surface sediments (0–5 cm) of three types of aquaculture ecosystems (seabass, white shrimp, and green crab ponds) reclaimed within the western bank of the Pearl River Estuary. Our results showed that no significant difference in sediment N mineralization and immobilization rates, microbial abundances, and organic matter among different aquaculture types on small-scale range. Meanwhile, prolonged pond-drying significant reduced sediment N mineralization and immobilization rates, bacterial abundances, organic matter, moisture content, ferrous ion (Fe2+), Fe2+/Fe3+, and ammonium (NH4+), while not strongly altered sediment percentage of NH4+ mineralized per day (PAM), relative ammonium immobilization (RAI), fungal abundances, TOC/TN, nitrate (NO3−), and δ13Corg. N mineralization and immobilization rates were both significantly related to overlying water NO3−, as well as sediment moisture content, bulk density, organic matter, Fe2+, and microbial abundances. In addition, the total mineralized and immobilized N in aquaculture surface sediments from the Guangdong-Hong Kong-Macao Greater Bay Area were estimated to be approximately 4.55×104 and 3.68×104 t N yr-1, respectively. Higher N mineralization relative to N immobilized fluxes indicated that the sediment serves as an important source of eutrophication in reclaimed aquaculture system of coastal wetlands.

The Impact of Recirculation on Extracorporeal Gas Exchange and Patient Oxygenation during Veno-Venous Extracorporeal Membrane Oxygenation-Results of an Observational Clinical Trial.

Recirculation during veno-venous extracorporeal membrane oxygenation reduces extracorporeal oxygen exchange and patient oxygenation. To minimize recirculation and maximize oxygen delivery (DO2) the interaction of cannulation, ECMO flow and cardiac output requires careful consideration. We investigated this interaction in an observational trial. In 19 patients with acute respiratory distress syndrome and ECMO, we measured recirculation with the ultrasound dilution technique and calculated extracorporeal oxygen transfer (VO2), extracorporeal oxygen delivery (DO2) and patient oxygenation. To assess the impact of cardiac output (CO), we included CO measurement through pulse contour analysis. In all patients, there was a median recirculation rate of approximately 14-16%, with a maximum rate of 58%. Recirculation rates >35% occurred in 13-14% of all cases. In contrast to decreasing extracorporeal gas exchange with increasing ECMO flow and recirculation, patient oxygenation increased with greater ECMO flows. High CO diminished recirculation by between 5-20%. Extracorporeal gas exchange masks the importance of DO2 and its effects on patients. We assume that increasing DO2 is more important than reduced VO2. A negative correlation of recirculation to CO adds to the complexity of this phenomenon. Patient oxygenation may be optimized with the direct measurement of recirculation.

Influence of four fiber-rich supplements on digestibility of energy and nutrients and utilization of energy and nitrogen in early and mid-gestating sows.

The digestibility of energy and nutrients in fiber-rich diets depends greatly on the fiber source but most data are from studies with growing pigs. The purpose of this study was to investigate the apparent total tract digestibility (ATTD) of nutrients in different fiber-rich diets and to quantify whole-body metabolism and utilization of energy and nitrogen (N) in gestating sows. Four fiber-rich diets based on sugar beet pulp (SBP), soy hulls (SH), palm kernel expellers (PKE), or a mixed fiber (MF) were formulated, with an average daily intake of total fiber (TF) of 471, 507, 651, and 437 g/d, respectively. A total of 48 multiparous sows were stratified by body weight at mating (day 0) and assigned to one of the four diets throughout gestation. Body weight and backfat were measured, and body pools of fat and protein were estimated using the deuterium oxide dilution technique at days 0, 30, and 60. On days 30 and 60, urine and fecal grab samples were obtained. On days 15 and 45, heart rate was measured to estimate total heat production. The ATTD of nutrients differed across treatments (P < 0.001), while in vivo organic matter digestibility deviated with up to ±3.3% units from in vitro enzyme digestibility of organic matter. The ATTD of energy was highly negatively correlated with intake of lignin (P < 0.001), while ATTD of N was highest (negatively) correlated (P < 0.001) with intake of insoluble non-starch polysaccharides (NSP). The ATTD of all nutrients except NSP was lowest in PKE-fed sows and highest, except for N, in sows fed the SBP diet. The ATTD of N was highest in the MF-fed sows and ATTD of NSP was lowest in the MF-fed sows. Sows lost most energy as heat (53% to 72% of gross energy intake), followed by energy in feces (15% to 17%), urine (3% to 4%), and methane (0.5% to 0.9%). Energy for maintenance accounted for the majority of the heat production and the total energy retention was lowest and highest in the SBP- and PKE-fed sows, with a retention of 3.3 and 13.3 MJ/d, respectively (P < 0.001). Sows lost most N through urine, the lowest and highest N loss (relative to intake) was observed in SH- and SBP-fed sows (50% to 63%, respectively), while 14% to 26% was retained as body protein. In conclusion, the fiber-rich diets were utilized efficiently by gestating sows with respect to energy with ATTD values above 82% in all four fiber-rich diets, whereas the high TF content in the diets compromised the N utilization in gestating sows.

Formulation of Effective Microorganism [EM] to Analyse its Impact on Municipal Wastewater Management

Discharging wastewater from households, industries, and other sources into the environment without treatment hurts the ecosystem as well as people’s quality of life by causing negative impacts on all living species, including health concerns to humans such as diarrhoea which kills 3,50,000 Indian children annually and only 33% of India’s urban wastewater is treated. The majority of energy is dedicated solely to the aeration process, which regulates the degradation of organic matter (sludge) found in wastewater, which is one of the most critical issues in wastewater treatment. As a result, the goal of this research is to develop long-term strategies for degrading organic materials using Effective Microorganisms Technology (EM). EM, also known as Effective Microorganism, is a carefully selected and proportioned liquid culture of fermenting microorganisms. In this study, three microorganisms were isolated from various sources, including soil, yogurt, and milk by serial dilution and spread plate technique, each isolate was made into a pure culture after incubation. They were identified by the VITEK method as Pseudomonas aeruginosa, Lactobacillus sporogenes, and Candida albicans. The microbial consortium was then formed by incubating all three organisms in a nutrient broth that had been modified. Each microorganism culture and formulated microbial culture were added to sewage samples taken in Erlenmeyer flasks. All samples were tested for physico-chemical parameters such as pH, BOD, COD, TDS, TSS, SO4 ²– and Cl- after a three-day incubation period at room temperature. The standard deviation method was used for statistical analysis and Microsoft Power BI was used to visualize the results. Lactobacillus sporogenes was the only culture that showed a significant reduction in all parameters except one when compared to other cultures that showed a reduction in most parameters except a few. As a result, Lactobacillus proved to be effective in wastewater treatment when compared with other cultures. Further research is required to determine its true potential.

Multi-drug and biocide-resistant Gram-positive bacteria prevalent on surfaces of veterinary clinics in Benue State, Nigeria

Objective: In this study, the common aerobic Gram-positive bacteria (GPB) contaminating veterinary clinic surfaces were isolated, and their susceptibility to antimicrobial agents (antibiotics and biocides) was determined. Materials and Methods: Standard cultural and biochemical procedures were used to process 62 swab samples collected from different surfaces in 4 veterinary clinics for the isolation and identification of GPB. The agar dilution technique was used to determine the sensitivity of the isolates to disinfectants, while the disc diffusion technique was used to determine the sensitivity to antibiotics. Results: Isolation rates in veterinary clinics I, II, III, and IV were 39.4%, 40.4%, 7.4%, and 12.8%, respectively. GPB were isolated from all the surfaces sampled. A total of 94 GPB isolates were recovered, comprising Bacillus species (51.1%), Staphylococcus species (38.3%), Corynebacterium species (6.4%), and Enterococcus species (4.3%). Only 13.8% of the GPB were resistant to at least one of the biocides tested. Multiple drug resistance to at least three classes of antimicrobial agents was exhibited by 95% of the isolates tested. Conclusion: The results of this study suggest that veterinary clinic environments and surfaces in Makurdi are reservoirs of wide varieties of antimicrobial-resistant GPB of veterinary and public health importance.

Distribution of Virulence Genes in Campylobacter spp. Isolated from Agaricus Mushrooms in Iran.

The white button mushroom (Agaricus) is a significant nutritional and therapeutic species utilized in the human diet and could transmit various bacterial infections. Campylobacter species are the most common cause of foodborne illness across the world. The present study has been planned to determine the frequency of virulence genes and antibiotic susceptibility test in Campylobacter spp. recovered from Agaricus mushroom. In this study, 740 Agaricus mushroom samples were gathered randomly from various markets from June 2020 to December 2020. Confirmation of Campylobacter spp. using biochemical analyses and 23S rRNA-based PCR was performed. The agar dilution technique was used to determine resistance to antibiotics using gentamicin (GM10μg), ciprofloxacin (CIP5μg), nalidixic acid (NA30μg), tetracycline (TE30μg), ampicillin (AM10μg), amoxicillin+ clavulanic acid (AMC30μg), erythromycine (E15μg), azithromycin (AZM15μg), clindamycin (CC2μg), and chloramphenicol (C30μg). Multiplex PCR was utilized to determine the prevalence of the recR, dnaJ, wlaN, virBll, cdtC, cdtB, cdtA, flaA, cadF, pidA, ciaB, ceuE, and cgtB genes. Campylobacter spp. were detected in 74 out of 740 Agaricus mushroom samples (10%). According to the data, Agaricus mushroom samples included 32 (4.32%) C. jejuni, 11 (1.48%) C. coli, and 31 (4.18%) other Campylobacter spp. Antimicrobial resistance was most common in C. jejuni isolates. C. jejuni isolates also had the lowest resistance rate to gentamycin, ciprofloxacin, and nalidixic acid. C. coli isolates were reported to have the highest antimicrobial resistance to ciprofloxacin, ampicillin, and erythromycine. Resistance to gentamycin and amoxicillin+ clavulanic acid was likewise lowest among C. coli strains. The flaA and ciaB genes were found in 100% of B-lactams-susceptible C. jejuni and C. coli strains. When examining the relationship between antibiotic resistance and the existence of virulence genes, it was observed that there is a statistically significant relationship (p < 0.001) between bacterial resistance and virulence genes. Our findings indicated that changes in resistance patterns in Campylobacter strains have emerged from multiple treatment approaches in Agaricus mushrooms.

Phytochemical Screening, Toxic Effects, and Antimicrobial Activity Studies of Digitaria abyssinica (Hochst. ex A.Rich.) Stapf (Poaceae) Rhizome Extracts against Selected Uropathogenic Microorganisms.

In Kenya, the D. abyssinica rhizome's decoction is traditionally used to treat urinary tract infections (UTIs), mainly gonorrhea and candidiasis. UTIs are the most severe public health problems that affect over one hundred and fifty million people worldwide annually. They are caused by a wide range of microorganisms where Escherichia coli is known to be the main causative pathogen. Medicinal plants are used in traditional Kenya set up for treatment and most recently as an alternative source of treatment for UTIs due to the increased cost of treatment and many challenges experienced with antibiotic therapy. The current study is designed to investigate the phytochemical composition, acute oral toxicity, and antimicrobial activity of Digitaria abyssinica rhizome extracts against Staphylococcus aureus, Escherichia coli, Neisseria gonorrhea, and Candida albicans. The rhizomes of D. abyssinica were obtained, dried, ground, and extracted using water and organic solvents. The phytochemical assay was carried out using standard phytochemical screening methods. Single-dose toxicity studies were done to determine LD50 while disk diffusion and microbroth dilution techniques were used to determine antimicrobial activity. Results revealed that saponins, phenolics, alkaloids, cardiac glycosides, tannins, flavonoids, steroids, and terpenes were present in the powder, aqueous, methanol, and dichloromethane : methanol extracts. All the extracts had an LD50 of above 2,000 mg/kg of body weight and there was no observation of behavioral changes. Also, the aqueous and methanol extracts revealed antifungal activity against Candida albicans with the lowest average minimum zone of inhibition at MIC of 31.25 mg/ml. The study did not reveal antibacterial activity for any extract against the studied uropathogenic bacteria, Staphylococcus aureus, Escherichia coli, and Neisseria gonorrhoeae. The results from the current study suggested that D. abyssinica rhizome aqueous and methanol extracts have potential antifungal activity against C. albicans, thus validating the folklore of its use to treat candidiasis.

DIOXINS, FURANS AND PCBS IN IMPORTED MARINE FISH – CONSUMER EXPOSURE

Background. Dietary guidelines recommend that fish should be consumed at least twice a week due to valuable nutrients they contain, like long-chain, polyunsaturated fatty acids, macro- and microelements, fat-soluble vitamins (mainly D3), amino acids and easily digestible protein. Apart from the benefits, fish consumption becomes a source of toxic compounds including polychlorinated dibenzo-p-dioxins (PCDDs), polychlorinated dibenzofurans (PCDFs) and polychlorinated biphenyls (PCBs). The aim of our research was to investigate the levels of PCDD, PCDF and PCB in marine fish imported to Poland and assess the risk for consumers, taking into account the tolerable weekly intake (TWI) of 2 pg WHO TEQ/kg body weight (b.w.). Six fish species were investigated: turbot, mackerel, Atlantic salmon, tuna, pollock and hake. The method employed for the research was isotope dilution technique with high resolution gas chromatography coupled with high resolution mass spectrometry (HRGC-HRMS). Results and conclusions. The highest concentrations for the sum of PCDD/F/dl-PCB were determined in turbot muscles 1.25 pg WHO-TEQ/g of fresh weight (f.w.) and the lowest in pollock, hake and tuna muscles 0.02, 0.03, 0.04 pg WHO-TEQ/g f.w. respectively. Although the tested fish contained low PCDD/F/PCB concentrations compared to the permissible limits, the consumption of the recommended two portions of the most contaminated species resulted in TWI being exceeded even six times for children and two times for adults. Imported turbot, salmon and mackerel are significant sources of dioxins and PCBs for fish consumer.

Response of Soil Microbial Community (Bacteria and Fungi) to Organic and Inorganic Amendments Using Tomato as a Test Crop

A field experiment was conducted to evaluate the response of soil microorganisms (bacteria and fungi), to some soil amendments (organic and inorganic) at site A and site B. The experiments were laid out in a randomized complete block design (RCBD). The treatments applied were compost (3.4 t/ha), poultry manure (4.2 t/ha), Tithonia diversifolia (4.8 t/ha), NPK (15:15:15) (0.8 t/ha) at 120 kg N/ha, and the control. Treatments were replicated three times. Tomato seedlings were raised in the nursery and transplanted to the field after 3 weeks with a spacing of 50 × 50 cm. Soil microbiomes (Fungi and Bacteria) were isolated using the serial dilution technique. Compost improved both the total number of fungi by 12%–178% and diversity by 1.09%–85% compared to the other amendments at both sites, while the diversity of bacteria was increased more by Tithonia diversifolia (11%–75%). The total number of bacteria was highest in plots amended with compost at site A. Compost had the highest percentage of bacteria suppressed compared to other amendments studied at both sites (27.3% and 28.5%, respectively). NPK had the highest bacteria suppression at site A. The plot amended with NPK had the highest percentage of bacteria enhanced at site A. NPK had the highest at site B. Poultry had the highest reduction in bacteria at site A. Tithonia diversifolia had the highest percentage proliferation of allochthonous bacteria at both sites with 23.7% and 27.7%, respectively, while compost plots had the least allochthonous bacteria at both sites. At both sites, the percentage of suppressed fungi was highest in plots amended with poultry manure and control. Compost and T. diversifolia had the highest percentage of fungus growth reduction in site A (26.3%). At site A, compost had the highest percentage of allochthonous fungi (29%). Application of compost, poultry manure, and Tithonia diversifolia is recommended for the improvement of soil microbial properties.

Isolation, and Characterization of Indigenous Rhizobacteria from Wheat (Triticum aestivum L.) and Determining their Drought Tolerance

Agricultural productivity is under serious threat as a result of the increased severity of droughts brought on by human activity and global warming. Hence, to ensure the security of the world's food supply, this has increased the demand for environmentally friendly alternatives. Numerous studies have associated the rhizobacteria that promote plant growth with the plants' adaptations to fluctuating environments. The present study was conducted over a period of 6 months, during which the drought tolerance potential of native bacteria from the Wheat (Triticum aestivum L.) rhizosphere was evaluated. A total of 10 different bacteria were isolated from the rhizosphere of flowering-stage wheat plants growing in the departmental garden of SSJ University, Almora, Uttarakhand by serial dilution technique. After a biochemical analysis, their drought tolerance potential was investigated and growth was monitored. Out of a total of ten isolates, only three were able to grow at 25% PEG. The ideal temperature range for the growth of these 3 rhizobacterial isolates was found to be 28-37℃. The present study highlights the role of rhizospheric bacteria in augmenting plant growth by providing drought tolerance.

Screening and Evaluation of Antimicrobial Activity of Medicinal Plants

Objectives: To screen and evaluate antimicrobial activity of crude ethanol extracts against various microorganisms. Methods: Ethanoic extracts of 7 different species; Acorus calamus (Bojho), Aloe vera (Ghiu Kumari), Artermisia indica (Titepate), Azadirachta indica (Neem), Mentha arvensis (Pudhina), Zanthoxylum armatum (Timur) and Zingiber officinale (Ginger) were subjected to soxhlet extraction. Test organisms included mainly enteric isolates i.e. Escherichia coli, Pseudomonas aeruginosa , Klebsiella oxytoca, Salmonella Typhi and Staphylococcus aureus were selected, pathogens confirmed by Antibiotic Susceptibility test was done by disc diffusion method of Modified Kirby – Bauer method using Amikacin (30 mcg), Ampicillin (10 mcg), Chloramphenicol (30 mcg), Ciprofloxacin (5 mcg), Gentamicin (10 mcg) and Penicillin G (10 mcg).The antimicrobial activities of the extracts were determined by Agar well diffusion technique both individually and in combination. On the other hand, Minimum Inhibitory Concentration (MIC) and Minimum Bactericidal Concentration was determined by dilution technique. Results: Among 7 plants that were tested, 6 plants were found to have activity against test bacteria. A. calamus was effective against 3 out of 5 test bacteria. A. indica and menthe arvensis inhibited 2 out of 5 bacteria. A. vera and A. indica were effective against S, aureus only and Z. officinale had no antibacterial effects over any tested bacteria. S. aureus was the most susceptible gram positive bacteria meanwhile K. oxytoca stood among Gram negative, emerged as the most resistant species. S. aureus showed ZOI with 6 plant extracts excluding ginger P. aeruginosa was inhibited by A. calamus, A. indica and M. arvensis. The largest ZOI of 15 mm was obtained with Z. armatum acting upon S. aureus. While the smallest diameter of 8 mm was observed with Acorus calamus against S. Typhi. The smallest MBC value of 13.63 mg/ml was obtained with M. arvensis against P. aeruginosa. Results showed that P. aeroginosa was the most resistant bacteria, only 1 out of 3 antibiotics were sensitive to it. 60% of the test bacteria were sensitive to 2 out of 3 antibiotics tested. Conclusion: To recapitulate, the extract of species can be used to prevent the pathogenic organism.

Analisa Total Bakteri Salmonella spp. pada Produk Ikan Cakalang Asap yang Dijual pada Beberapa Pasar di Kota Ambon

Skipjack tuna (Katsuwonus pelamis) is one of the dominant capture fisheries products in Maluku. This is supported by the geographical location of the Maluku Islands which are surrounded by the sea. Bacteria are often found in traditional processed fishery products such as smoking fish. This study aims to determine the total bacteria Salmonella spp. and differences in the abundance of Salmonella spp. on smoked skipjack (Katsuwonus pelamis) products sold in several markets in Ambon City. This research is an experimental research. The research was carried out by taking samples with a total of 5 samples from the people's market location, and bacterial calculations were carried out using a dilution technique. Bacteria that have been obtained from the dilution results, then isolated using the quadrant scratch method technique on SSA media (Salmonella Shigela Agar). Bacterial biochemical tests, including: indole test, Methyl-Red test, Voges Proskauer test, citrate test, and Triple Sugar Iron Agar (TSIA) test, and gram staining were performed to confirm/identify the isolated bacteria. The results showed that smoked skipjack sold at Mardika Market was identified as having the total number of Salmonella spp. respectively 6700 CFU/ml and 8400 CFU/ml. The total number of Salmonella spp. on smoked skipjack at Mardika market is different from the results of the calculation of the total bacteria of smoked skipjack sold in modern markets and small hative markets, which did not identify any Salmonella spp bacteria contamination.

Effect of ivermectin on the prevalence of gastrointestinal parasites in Jamuna basin sheep

The effect of ivermectin on the prevalence of gastrointestinal parasites of Jamuna basin sheep was investigated in relation to the areas, flock sizes and rearing systems. A total 420 faecal samples were examined microscopically by using Stoll’s ova dilution technique from June to December 2020. The number of eggs per gram of feces was calculated and it ranged from 100-500.The study showed that 100% sheep were found to be infected with one or more species of parasites. Four types of parasites were identified. In grazing animals, stomach worm, Paramphistomum worm, Fasciola and install feeding, stomach worm and Trichuris were found. The prevalence of parasites in grazing on 0 day was stomach worm 20%, Paramphistomum worm10% whereas in stall feeding it was stomach worm 15% and Trichuris 10%. In 15 days, in all grazing animals stomach worm was 10% and Paramphistomum worm 10% whereas in stall feeding it was stomach worm 5%. On 30th day, in grazing animals, stomach worm 15%, and Paramphistomum worm 10% were present, whereas in stall feeding it was stomach worm 10%, and Paramphistomum 10%. The highest prevalence of stomach worm was 20%, whereas Paramphistomum was the lowest with 10% as seen ingrazing animals. Stomach worm with 15% was the highest and theTrichuris with 10% was the lowest in stall feeding animals. Prevalence of parasites increased with the flock size on 0 day and ivermectin injection reduced the prevalence in 15 days and later it increased after 30 days of interval. The prevalence was higher in char area (35%) than the hilly area (15%). The sheep were more affected in grazing (25%) than stall feeding (20%). In conclusion, the use of ivermectin injection reduced the prevalence of gastrointestinal parasites up to one month in sheep. SAARC J. Agric., 20(2): 235-245 (2022)

Essential Oils Composition, Antibacterial Activity and Toxicity Study of Artemisia Species Growing in Ethiopia

Artemisia essential oils have been used in flavors, scents, mice repellents, cleansers, beauty care products, fragrances, and conventional pharmaceuticals. This work analyzed the phytoconstituents, in vitro antibacterial activity, and toxicity of essential oils of three Artemisia species growing in Wolaita, Ethiopia. GC-MS has been used to analyze chemical composition. In vitro antibacterial activity was assessed by disc diffusion and broth dilution techniques. The MTT assay was used to conduct toxicity studies. The main components of the essential oil extracted from Artemisia afra Jacq. ex Willd. were camphor (19.2%), followed by 1,8-cineole (17.8%), artemisia ketone (15.2%), artemisyl acetate (6.9%), and camphene (6.6%). In the Artemisia annua L. oil, the main constituents were camphor (21.8%), artemisia alcohol (18.1%), santolina triene (11.6%), -copaene (9.1%), sabinene (4.5%), and δ-cadinene (4.0%). In addition, the main phytochemicals of Artemisia abyssinica Sch.Bip. ex A.Rich. oil were yomogi alcohol (39.3%), followed by cis β-farnesene (10.9%), β-selinene (6.7%), β-copaene (5.2%), and nerolidol (5.1%). The essential oils of A. afra, A. annua, and A. abyssinica showed significant antibacterial activity at low molar concentrations, with MIC values of 0.31, 0.15, and 0.62 μL against Staphylococcus aureus and 0.62, 0.31, and 1.25 μL against E. coli, respectively, compared with standard broad-spectrum gentamicin (0.25 μL). A. afra, A. annua, and A. abyssinica oils were showed weak toxicity to Vero cell lines with IC50 values of 178.47 µg/mL, 183.86 µg/mL, and 187.46 µg/mL, respectively. This result suggests that EOs are promising antibacterial agents given their weak toxic effects on normal cell lines at low concentrations.

Influence of diet formulation technique on requirement of digestible lysine for growing Japanese quail: A practical reflection

This work aimed to investigate the influence of two diet formulation techniques: supplementation and dilution, on estimates of digestible lysine requirements in growing Japanese quail. For this, 492 Japanese quails (10 to 36 days old) with initial weight of 33.7 ± 0.42 g were used, housed in overlapping cages, and distributed in a completely randomized design in a 2 × 5 factorial arrangement. Two formulation techniques (supplementation technique and dilution technique) and five levels of lysine (0.80; 0.90; 1.00; 1.10 and 1.20%) were used, thus composing 10 treatments and 6 repetitions with 8 birds each. Performance parameters, nutrient gain, and carcass components were evaluated. There was interaction (p <0.05) between the formulation techniques and the levels of digestible lysine tested for feed intake, weight gain, protein gain, fat gain, chilled carcass weight, breast weight and thigh percentage, in addition to the isolated effect of the formulation technique on feed conversion, and isolated effect of the levels of digestible lysine on feed conversion and thigh weight. The digestible lysine requirement values estimated for better performance and efficiency in nutrient deposition were 1.028% or 133 mg/day by the supplementation technique, and 1.063% or 140 mg/day by the dilution technique. It can be concluded that the requirement for digestible lysine in Japanese quail is influenced by the formulation technique, and the supplementation technique had better results.

Investigation of the synergistic effect of glycolipid biosurfactant produced by Shewanella algae with some antibiotics against planktonic and biofilm forms of MRSA and antibiotic resistant Acinetobacter baumannii.

To tackling antibiotic resistance and the appearance of multidrug-resistant (MDR) strains, one current approach is the combined use of biosurfactants with antibiotics to increase their efficacy. The antimicrobial ability of biosurfactant produced by Shewanella algae strain B12 was examined using the agar well diffusion method versus some resistant Gram-negative and Gram-positive bacteria. The Minimum Inhibitory Concentration (MIC) of Glycolipid-Biosurfactant of B12 (GBB12) was performed by the broth dilution technique. The inhibition of biofilm formation, disruption of biofilm, and reducing the population of viable cells in biofilm were evaluated by the microtiter plate method. Finally, Scanning Electron Microscopy (SEM) analysis was used to confirm the disruption of the cell membrane by GBB12. In all experiments, when GBB12 was added to antibiotics (except Amikacin), the antimicrobial activity was increased. The synergistic effects of GBB12 and antibiotics (Ciprofloxacin and Gentamycin) against Methicillin-Resistant Staphylococcus aureus (MRSA) and Acinetobacter baumannii were confirmed by the Fractional Inhibitory Concentration Index (FICI). GBB12-Gentamycin mixture almost completely inhibits the formation of A. baumannii biofilm, reaching 99.8% inhibition. Also, the rate of MRSA biofilm inhibition treated with GBB12-Ciprofloxacin mixture was found to be 99.4%. biosurfactant-antibiotic mixture could be adequate replacements for traditional antibiotics in the near future. This study shows the potential of GBB12 as antimicrobial and antibiofilm agent.

Isolation and Characterization of Antibiotic Producing Fungi from Soil

This study was aimed to isolate and characterize antibiotic producing fungi from the soil environment within Ahmadu Bello University main campus Samaru, Zaria. Soil samples were collected from five different locations within Ahmadu Bello University main campus for the Isolation of fungi. Spread plate method involving serial dilution technique was used for the Isolation using Saboraud Dextrose Agar (SDA). Six species of fungi were isolated from the soil samples and then characterized microscopically and macroscopically. The fungi were Aspergillus niger, Aspergillus fumigatus, Aspergillus sp, Penicillium sp, Fusarium sp (P14) and Fusarium sp (P15). Sensitivity test using Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae as test pathogens was employed to determine the ability of the fungal isolates to produce antimicrobials. All the fungal isolates were found to inhibit the growth of at least one of the test pathogens except Fusarium sp (P14). Aspergillus niger produces zones of inhibition of 9mm, 5mm and 6mm against Staphylococcus aureus, Escherichia coli, and Klebsiella pneumoniae, Aspergillus fumigatus produces zones of inhibition of 5mm against Escherichia coli and Klebsiella pneumoniae. Aspergillus sp produced zones of 6mm against Staphylococcus aureus and Escherichia coli, Penicillium sp which produces a zone of 10mm, 7mm and 6mm against Staphylococcus aureus, Escherichia coli and Klebsiella pneumoniae. The findings of this study show that antibiotic-producing fungus are prevalent in the soil of Ahmadu Bello University's main campus in Samaru, Zaria, and that these strains could be used by pharmaceutical companies to produce antibiotics from local sources.

In vitro antibacterial activities of essential oils and extracts of six herbals against gram-positive and gram-negative bacteria

Considering the development of bacterial resistance to chemical antibiotics and their adverse effects on the environment and public health, there is a growing demand to replace them with plant-based derivatives or combine these green agents with antibiotics to give synergistic effects. In this study, the antimicrobial properties of essential oils and extracts of six medicinal plants from Ahvaz region, Iran, against 12 gram-positive and gram-negative bacteria were evaluated. The EOs and extracts were extracted using water distillation with Clevenger apparatus. We analyzed the chemical composition of essential oils obtained. The antimicrobial properties and determination of the minimum concentration of growth inhibition of herbals were investigated by the broth dilution technique. All analyzed extracts and EOs showed antibacterial effects. The antimicrobial activity of Oliveria decumbens was strongest herbals with the least MIC ranges (0.008–0.1 mg/ml for EO, 0.9–20 mg/ml for extract), while the antibacterial effects of Artemisia vulgaris extract and Glycyrrhiza glabra EO with the highest MIC were weaker than the others. According to the effectiveness of plant extracts on bacteria, Pseudomonas aeruginosa was resistant to all extracts except Oliveria decumbens. In contrast, Bacillus cereus was more sensitive than other strains against analyzed EOs and extracts. In Oliveria decumbens, EO detected 18 components by GC/MS with accessible genuine standards, accounting for 98% of the oil content. It seems that due to the antimicrobial properties of the extracts and essential oils observed in this study, they can be used as an alternative to antimicrobial drugs after more extensive studies.

MICROBIOLOGICAL AND PHYSICOCHEMICAL QUALITIES OF IKPOBA RIVER IMPACTED BY PIPED TREATED BREWERY EFFLUENT STREAM

The impact of discharged treated brewery effluent stream on the microbial andphysicochemical qualities of Ikpoba River which is serving as a receptacle for the treatedwastewater was investigated. Serial dilution, pour plate and multiple tube technique wereemployed in evaluating the culturable microbial diversity of the water samples and thetreated brewery wastewater. The physicochemical attributes of the freshwater and effluentsamples were ascertained using titrimetric and spectrophotometric procedures. The meanheterotrophic bacterial counts for the upstream freshwater samples ranged from 3.7 ×102cfu/ml ± 2.1 to 0. 6 × 102 cfu/ml ± 2. The mean heterotrophic fungal counts for watersamples obtained at the point of discharge ranged from 0.7×103 cfu/ml ± 6.6 to 9.7 × 103cfu/ml ± 6.1. The total coliform counts recorded for water samples obtained at thedownstream sampling point ranged from 2 MPN/105 ml to 5 MPN/105 ml. The E. colicounts for the treated brewery wastewater varied from 2 MPN/105 ml to 4 MPN/105 ml. Theobserved differences in the mean heterotrophic bacterial and fungal counts was statisticallysignificant (P&lt;0.05). Seven bacterial and four fungal isolates were characterized andtentatively identified; Proteus vulgaris, Bacillus cereus, Klebsiella pneumoniae, Escherichiacoli, Streptococcus sp., Pseudomonas sp., Enterobacter aerogenes, Saccharomycescerevisiae, Candida tropicalis, Penicillium sp. and Aspergillus niger. The mean pH, turbidityand conductivity of the respective samples ranged from 5.63±0.05 to 6.78±0.05, 4.1 NTU±0.21 to 6.81 NTU ±0.55 and 3.3 ?s/cm ±0.25 to 73.3 ?s/cm ±6.56 respectively. Thedischarged brewery effluent stream impacted negatively on the as aesthetic quality of theIkpoba River at the point of discharge. The microbiological quality of both the watersamples and the treated effluent is very poor when compared with Federal Ministry ofEnvironment limits for potable water, hence discouraging the direct consumption of thewater sourced from the Ikpoba River at these sampling points by individuals living along thecatchment area of the river

Investigation of the mycological infection of animal feeds in western Algeria

Contamination of livestock feed is a serious problem worldwide during storage. Fungal infection reduces nutritional quality of feed and affects the animal health, thus reducing the livestock profitability. The aim of this study was to investigate the mycoflora of 73 samples representing four raw cereals; (corn, barley, soybean and wheat bran) and three concentrate finished feed of (dairy cow, poultry and pellet). Isolation of internal and external mycoflora was carried out using dilution plate and direct plate methods. The result of the dilution technique revealed that Aspergillus, Penicillium, Fusarium and Alternaria were the most frequently occurring genera. The analyzed samples showed fungal contamination ranging from 18.84 × 103 CFU/g to 55.23 × 103 CFU/g. Comparing the different feed types, finished concentrates had greater fungal contamination compared to the raw ingredients. The most directed external mycoflora in corn, barley and soybean, using the direct plate technique were Aspergillus (100%, 85.66%, 75%) and Penicillium (83.33%, 50%, 50%) respectively. However, Atlernaria (83.33%, 57% and 75%) and Fusarium (66.33%, 71.33% and 50%) were the most predominant internal mycoflora genera. The overall percentage of fungal infection was higher in non-surface disinfected seeds compared to surface disinfected ones. Fungal infection affected quality of grain through reduction in germination. It seems that livestock feed is highly affected by fungi and special storage and conditioning are required to reduce the fungal infection and protect the animal and human health.