Sources Peptone Research Articles

Characterization of the Beauveria bassiana ga fungal strain isolated from the muscardine infected silkworms (Bombyx mori L.)

In this study, the focus was on isolating and characterizing the fungal strain Beauveria bassiana from muscardine-infected silkworms (Bombyx mori L.). The fungal strain isolated from the muscardine-infected silkworm, designated as GA, closely resembled Beauveria bassiana isolate SBI-Bb04 based on morphological analysis and comparison of the 18S rRNA nucleotide sequence with sequences in the NCBI database. Beauveria bassiana GA demonstrates the ability to grow on Sabouraud Dextrose Agar (SDA) medium. Optimal conditions for its growth were determined to be a pH range of 6-7 and a temperature range of 20-25°C. The composition of SDA, containing glucose and peptone sources, was found to be ideal for both growth and sporulation of this fungal strain. Furthermore, Beauveria bassiana GA exhibits the capacity to synthesize various extracellular enzymes, including chitinase, protease, cellulase, and amylase. These enzymatic activities contribute to its pathogenicity and suggest its potential as a biocontrol agent against insect pests.

Isolation of a Novel Amylase Producing Brachybacterium paraconglomeratum Strain FAD4 and Optimization of the Enzyme Production Conditions

A novel amylase producing bacterium FAD4 was isolated from the wastewater of a textile factory located in Soke (Aydın/Turkey). The amylase production ability of gram positive, coccoidal FAD4 strain was confirmed with plate assay. Morphological and 16S rRNA sequence analyses revealed that FAD4 belongs to the Brachybacterium paraconglomeratum species with a sequence similarity of 99.8%. The optimal conditions for amylase production were determined as 72 h at 30 °C with supplementation of 1% starch. Optimum temperature and pH of the amylase were 50 °C and 7.0 respectively. Different starch, carbon and nitrogen sources were investigated for amylase production. A high enzyme production was observed with 1% potato starch and among nitrogen sources peptone was induced the production of amylase. Lactose, galactose, and fructose were also increased the enzyme production as carbon sources.

Influence of different Carbon and Nitrogen Sources on the Production of Single Cell Biomass from Potato Peels

Potato peel can be converted into various value-added compounds, such as enzymes, bio sorbents, biohydrogen, and biogas. Objective: To evaluate the influence of different Carbon and Nitrogen Sources on the Production of Single Cell Biomass from potato peels. Methods: The process of fermentation was carried out in mix broth with different concentrations of carbon, nitrogen, and different nitrogen sources to determine the effect of these factors on the production of SCP. Results: Maximum yield of dry cell biomass (0.251 and 0.245 g/100 ml) was achieved with organic nitrogen source peptone and inorganic nitrogen source ammonium sulphate, respectively. Ammonium sulphate is more suitable to use as peptone is expensive organic nitrogen source. Next optimization of nitrogen concentration was done with ammonium sulphate with different concentrations and best yield (0.190 g/100 ml) was obtained with 1.5% nitrogen concentration. Conclusions: In conclusion, the study suggests that ammonium sulphate is a more suitable nitrogen source than peptone for maximizing the yield of dry cell biomass. Additionally, optimization of nitrogen concentration with ammonium sulphate showed that a 1.5% concentration is the best for achieving the highest yield. These findings have important implications for improving the efficiency and cost-effectiveness of industrial-scale production of dry cell biomass

Use of wool protein hydrolysate as nitrogen source in production of microbial pigments

This study investigated the usability of sheep wool peptone (SWP) as an organic nitrogen source in production of pigments from the bacterium Serratia marcescens and the yeast Rhodotorula glutinis. SWP was prepared from sheep wool by KOH hydrolysis and H3PO4 neutralization. The potantial of SWP on pigment synthesis was compared with commercial tryptone peptone (TP) and proteose peptone (PP). The effectiveness of peptones on pigment synthesis was tested at different culture pHs and peptone concentrations in shaking flask culture. An initial medium pH of 7.0 and a peptone concentration of 6 g/L were found to be optimal for carotenoid synthesis in R. glutinis, but an initial culture pH of 8.0 and a peptone concentration of 8 g/L for prodigiosin synthesis in S. marcescens. In SWP, TP and PP-based cultures; prodigiosin concentrations of 341, 175, and 302 mg/L; and carotenoid concentration of 94, 88, and 80 mg/L were reached. Novelty impact statement Commercial peptones or protein hydrolysates are extensively used as organic nitrogen source in production of microbial pigments; however, high price of peptones restricts their use for this purpose. The present study revealed that protein hydrolysate prepared from sheep wool could be used as a peptone source in production of pigments from the yeast Rhodotorula glutinis and the bacterium Serratia marcescens. SWP was found to be superior to commercial peptones for production of both R. glutinis and S. marcescens pigments. Usability of wool protein hydrolyzate as an organic nitrogen source or peptone in production of microbial pigments was tested for the first time in the present study.

Bioconversion of waste sheep wool to microbial peptone by Bacillus licheniformisEY2

AbstractPeptones are among the most expensive culture components used in the cultivation of microorganisms. This study was performed to prepare a protein hydrolysate from sheep wool using a locally isolated keratinolytic bacterium Bacillus licheniformis EY2 (GenBank: MN809476), and to investigate the usability of the prepared hydrolysate as a peptone in a microbial medium. The optimum pH, temperature, and incubation time for wool hydrolysis and keratinolytic activity were determined as 7.0, 55 °C, and 6 days, respectively. Optimum concentrations of KH2PO4, MgSO4, and NaCl were determined as 1.5, 0.5, and 2 g/L, respectively. After the prepared hydrolysate was partially purified, it was converted to wool peptone (WP). The total protein, ash, carbohydrate, and lipid content of WP was found to be 82.7, 7.2, 0.1, and 0.2 g/100 g, respectively. Fourier transform infrared (FTIR) analysis of WP confirmed the formation of sulfoxide bonds (S=O), which indicated the breaking of disulfide bonds. When compared with commercial tryptone peptone (TP), WP was found to be superior for the cell growth performances of Esherichia coli, Bacillus subtilis, Staphylococcus aureus, Lactobacillus plantarum, Pediococcus pentosaceus, Candia albicans and Aspergillus niger. A protein hydrolysate (including wool protein hydrolysate) prepared via microbial hydrolysis was tested for the first time as a peptone source. The cost of WP is much lower than commercial peptones. At the same time, the method developed offers an environmentally friendly approach for the reduction of the amount of unutilized or waste sheep wool. © 2021 Society of Industrial Chemistry and John Wiley & Sons Ltd.

Characterization, application and statistical optimization approach for enhanced production of pyocyanin pigment by Pseudomonas aeruginosa DN9

The aim of this work was to study the pyocyanin pigment from Pseudomonas aeruginosa DN9. The work involves optimization of process parameters for enhanced production of pyocyanin pigment under submerged fermentation condition. During optimization process, maximum pyocyanin production (92.12 µg/ml) was obtained with carbon source mannitole, nitrogen source peptone, inorganic salt NaCl and metal ion FeSO4. Plackett Burman design and Response Surface Methodology (RSM) showed peptone, NaCl and KH2PO4 are significant variable in the production of pyocyanin pigment. The FTIR and GC–MS study was done to evaluate structural properties of pyocyanin pigment. The purified pigment was further analyzed as colouring agent and for inhibitory action against pathogenic microorganisms. Thus, present study showed Pseudomonas aeruginosa DN9 as promising culture for pigment production with potential biotechnological application.

Evaluation of peptones from chicken waste as a nitrogen source for micro-organisms.

In this study, chicken peptone was produced by hydrolysing inedible parts derived from chickens using endo-protease and exo-protease. The usefulness of chicken peptone as a nutrient source for bacteria was evaluated in comparison with other commercially produced peptones (animal, soy and casein-derived peptone). Escherichia coli and Bacillus subtilis were used as test strains to determine the effect of peptones from different sources on their growth ability. Both bacteria were successfully cultured in chicken peptone solution, which is similar to peptone solution containing commercial peptones apart from animal peptone. In chemical analysis, chicken peptone contained 12·0% nitrogen; this was similar to the nitrogen content from other commercial peptone sources, except for the 9·0% nitrogen found in soy peptones. The molecular weight of the peptone was determined by gel filtration chromatography, and those of all peptone, except animal-derived peptone, were found to be <5000Da. In addition, when B. subtilis was cultured in a medium containing chicken peptone, it was shown that the protease activity was highest as compared with other commercial peptones. From these results, it is suggested that chicken peptone can be utilized for microbial culture, and this is an effective method to reuse chicken waste.

Chicken Feather Hydrolysate as Potential Peptone Source for Bacterial and Yeast Cultivation

Chicken Feather Hydrolysate as Potential Peptone Source for Bacterial and Yeast Cultivation

Chicken feather hydrolysate as alternative peptone source for microbial cultivation.

Background: Commercially available conventional growth media for the culture of microbes are expensive, hence the need for alternative cheaper sources. Livestock waste, in the form of feather and blood, are of value in biotechnology because of their high protein content. Hence the primary aim of this study was to produce a cheaper peptone alternative from chicken feather protein hydrolysate (CFPH) and blood meal (BM). Methods: The growth of selected bacteria and fungi was monitored in different media prepared from varied concentrations of peptone, CFPH and BM in order to determine the combination that produced maximum growth. Five different media, namely 100% peptone (control), 100% BM, 40% peptone + 60% CFPH, 40% BM + 60% CFPH and 20% peptone + 20% BM + 60% CFPH were prepared and used for the study. The different media were inoculated with 1 ml of each test organism ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida carpophila, Candida tropicalis and Pichia kundriavzevii) and their growth monitored for 10 h. Results:Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus grew best in the 100% peptone, Klebsiella pneumoniae grew best in 100 BM. The fungi species were observed to grow best in 100% peptone. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of trichloroacetic acid (TCA), hydrochloric acid (HCl) and nitric acid (HNO 3) gave the best growth of E. coli. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA) also gave the best growth of C. tropicalis and Klebsiella pneumoniae. Conclusions: Overall, the 60% CFPH + 40% peptone combination showed the most potential as an alternative to peptone, especially for E. coli.

Novel Fibrinolytic Protease Producing Streptomyces radiopugnans VITSD8 from Marine Sponges.

Fibrinolytic enzymes have received more attention due to their medicinal potential for thrombolytic diseases. The aim of this study is to characterize the in vitro fibrinolytic nature of purified protease producing Streptomyces radiopugnans VITSD8 from marine brown tube sponges Agelas conifera. Three varieties of sponge were collected from the Rameshwaram Sea coast, Tamil Nadu, India. The fibrinolytic activity of Streptomyces sp. was screened and determined by casein plasminogen plate and fibrin plate methods respectively. The crude caseinolytic protease was purified using ammonium sulfate fractionation, affinity and ion-exchange chromatography. Based on the morphological, biochemical, and molecular characterization, the isolate VITSD8 was confirmed as Streptomyces radiopugnans. Maltose and peptone were found to be the best carbon and nitrogen sources for the production of fibrinolytic protease. The carbon and nitrogen source peptone showed (781 U/mL) enzyme activity. The optimum pH and temperature for fibrinolytic protease production was found to be 7.0 and 33 °C respectively. The purified enzyme showed a maximum specific activity of 3891 U. The blood clot lysis activity was compared with the standard, and it was concluded that a minimum of 0.18 U (10 µL) of purified protease was required to dissolve the blood clot. This is the first report which exploits the fibrinolytic protease activity of Streptomyces radiopugnans VITSD8 extracted from a marine sponge. Hence the investigation suggests a potential benefit of purified fibrinolytic protease which will serve as an excellent clot buster alternative.

Chicken feather hydrolysate as alternative peptone source for microbial cultivation.

Background: Commercially available conventional growth medium for the culture of microbes are expensive, hence the need for alternative cheaper sources. Poultry waste, in the form of feather and blood, are of value in biotechnology because of their high protein content. Hence the primary aim of this study was to produce a cheaper peptone alternative from chicken feather protein hydrolysate (CFPH) and blood meal (BM). Methods: We monitored the growth of selected bacteria and fungi in different concentrations of medium produced from varying combination of peptone, CFPH and BM in order to determine the combination that produced maximum growth. Five different media, namely 100% peptone (control), 100% BM, 40% peptone + 60% CFPH, 40% BM + 60% CFPH and 20% peptone + 20% BM + 60% CFPH were prepared and used for the study. The different media were inoculated with 1 ml of each test organism ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida carpophila, Candida tropicalis and Pichia kundriavzevii) and their growth monitored for 10 h. Results:Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus grew best in the 100% peptone, Klebsiella pneumoniae grew best in 100 BM. The fungi species were observed to grow best in 100% peptone. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of trichloroacetic acid (TCA), hydrochloric acid (HCl) and nitic acid (HNO 3) gave the best growth of E. coli. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA) also gave the best growth of C. tropicalis and Klebsiella pneumoniae. Conclusions: Overall, the 60% CFPH + 40% peptone combination showed the most potential as an alternative to peptone, especially for E. coli.

Chicken feather hydrolysate as alternative peptone source for microbial cultivation

Background: Commercially available conventional growth media for the culture of microbes are expensive, hence the need for alternative cheaper sources. Livestock waste, in the form of feather and blood, are of value in biotechnology because of their high protein content. Hence the primary aim of this study was to produce a cheaper peptone alternative from chicken feather protein hydrolysate (CFPH) and blood meal (BM). Methods: The growth of selected bacteria and fungi was monitored in different media prepared from varied concentrations of peptone, CFPH and BM in order to determine the combination that produced maximum growth. Five different media, namely 100% peptone (control), 100% BM, 40% peptone + 60% CFPH, 40% BM + 60% CFPH and 20% peptone + 20% BM + 60% CFPH were prepared and used for the study. The different media were inoculated with 1 ml of each test organism ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida carpophila, Candida tropicalis and Pichia kundriavzevii) and their growth monitored for 10 h. Results: Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus grew best in the 100% peptone, Klebsiella pneumoniae grew best in 100 BM. The fungi species were observed to grow best in 100% peptone. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of trichloroacetic acid (TCA), hydrochloric acid (HCl) and nitric acid (HNO 3) gave the best growth of E. coli. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA) also gave the best growth of C. tropicalis and Klebsiella pneumoniae. Conclusions: Overall, the 60% CFPH + 40% peptone combination showed the most potential as an alternative to peptone, especially for E. coli.

Genetic identification and optimization of novel β-glucosidase-producing Lysinibacillus sphaericus QS6 strain isolated from the Egyptian environment

Background and objective β-Glucosidase-producing bacteria are potential sources for biotransformation of lignocellulose biomass and agricultural wastes into biofuels. The aim was the isolation, screening, molecular identification, and optimization of highly efficient β-glucosidase-producing bacteria under different growth conditions. Materials and methods Cellulose-degrading bacteria were isolated and screened for β-glucosidase enzymes. Then, they were identified by phenotypic and genotypic identification. Optimization for β-glucosidase production was studied under different culture conditions. Results and conclusion Highly efficient β-glucosidase-producing strain QS6 was selected and identified morphologically and biochemically as Lysinibacillus sp. using 16 s rDNA gene sequencing approach and bioinformatics analysis. Strain QS6 was most similar to Lysinibacillus sphaericus, with similarity of 98%. Phylogenetic analysis was done to determine the relationship of strain QS6 with different strains of genus Lysinibacillus sp. It indicated that the suitable culture conditions of producing β-glucosidase were the culture temperature of 35°C, the initial pH of 7.0, the incubation time of 24 h, and 1% inoculum size. While studying the effect of carbon sources on β-glucosidase production, it was found that cellobiose (1%w/v) was the best carbon source for inducing β-glucosidase production. Moreover, the nitrogen source peptone at 0.5% w/v was optimum for β-glucosidase production by this bacterium. L. sphaericus QS6 was found to be sensitive to antibiotics (amoxicillin, streptomycin, tetracycline, cefadroxil, kanamycin, chloramphenicol, ampicillin, erythromycin, and tobramycin). Moreover, in-vitro antibacterial bioassay of the most potent β-glucosidase-producing strain (QS6) showed high antimicrobial activity against Escherichia coli (1.9 cm) and Pseudomonas aeruginosa 1.0 cm). A promising Lysinibacillus sp. completely identified as L. sphaericus QS6 (GenBank MN493725.1) is an efficient source of β-glucosidase production.

Chicken feather hydrolysate as alternative peptone source for microbial cultivation.

Background: Commercially available conventional growth medium for the culture of microbes are expensive, hence the need for alternative cheaper sources. Poultry waste, in the form of feather and blood, are of value in biotechnology because of their high protein content. Hence the primary aim of this study was to produce a cheaper peptone alternative from chicken feather protein hydrolysate (CFPH) and blood meal (BM). Methods: We monitored the growth of selected bacteria and fungi in different concentrations of medium produced from varying combination of peptone, CFPH and BM in order to determine the combination that produced maximum growth. Five different media, namely 100% peptone (control), 100% BM, 40% peptone + 60% CFPH, 40% BM + 60% CFPH and 20% peptone + 20% BM + 60% CFPH were prepared and used for the study. The different media were inoculated with 1 ml of each test organism ( Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, Staphylococcus aureus, Pseudomonas aeruginosa, Candida carpophila, Candida tropicalis and Pichia kundriavzevii) and their growth monitored for 10 h. Results:Pseudomonas aeruginosa, Proteus mirabilis and Staphylococcus aureus grew best in the 100% peptone, Klebsiella pneumoniae grew best in 100 BM. The fungi species were observed to grow best in 100% peptone. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA, HCl, and HNO 3 gave the best growth of E. coli. The 60% CFPH + 40% peptone combination (CFPH obtained with precipitate of TCA) also gave the best growth of C. tropicalis and Klebsiella pneumoniae respectively. Conclusions: Overall, the 60% CFPH + 40% peptone combination showed the most potential as an alternative to peptone, especially for E. coli.

Enhancement of Amylase and Lipase Production from Bacillus licheniformis 016 Using Waste Chicken Feathers as Peptone Source

Peptones are accepted as one of the most expensive medium components of microorganisms. The present study was undertaken to investigate the effect of chicken feather peptone (CFP) on enzyme (lipase and amylase) production by Bacillus licheniformis 016. In order to assess its effectiveness on enzyme production, CFP was compared with commercial fish peptone (FP) and protease peptone (PP). The optimum concentration of CFP for lipase and amylase production was determined as 5 and 6 g/L, respectively. The optimum concentration of both FP and PP was found as 4 g/L for lipase production and 5 g/L for amylase production. In all the peptone media, the optimal incubation times for amylase and lipase production were determined as 24 and 48 h, respectively. CFP was found to be more favorable for lipase and amylase production. In CFP, PP and FP media, the maximum lipase activities were 1870, 1582 and 1831 U/L, and the maximum amylase activities were 1680, 1505 and 632 U/L, respectively. On the other hand, better cell growth performance was achieved in CFP media compared to PP and FP media. The least pH change was detected in CFP-containing media. CFP was also found to prevent starch aggregation in the medium in contrast to FP and PP. This study exhibited that CFP was a better nitrogen source or an inducer for lipase and amylase production as well as cell growth in comparison to the tested commercial peptones.

English

Lipases catalyze the hydrolysis of long chain triglycerides. Microbial lipases are receiving much attention because of their industrial potential in the chemical, pharmaceutical, medical, cosmetic, biosurfactant synthesis, leather industries, mutation, agrochemicals and paper manufacturing industries. This article presents the isolation of maximum lipase producing bacteria and the optimization of different conditions for the maximum production of lipase. Bacillus subtilis PCSIRNL-39 shows maximum production of lipase at 45°C with pH 7 using nitrogen source peptone and carbon source sucrose. B. subtilis PCSIRNL-39 showed the best production at 5% inoculum size, while Ca2+ and Mg2+ were found best stimulator for enzyme production during the study. Tween 20 and 80 enhanced better lipase production than other surfactant. The kinetic parameters of Vmax and Km for the lipase were measured to be 101 µM/min.mL and 7.6 mg, respectively. Key words: Bacillus subtilis, microbial lipase, production, optimization.

Evaluación del enriquecimiento proteico de residuos de papa y yuca con (Paecilomyces variotti)

Los problemas de suministro de proteína hacen necesaria la búsqueda de alternativas distintas a las fuentes tradicionales. La proteína microbiana, celular o unicelular (PUC), es una opción favorable. Una de las ventajas de la PUC, es que emplea como sustratos residuos de actividades industriales y desechos de poscosecha, como residuos agroindustriales (RA). Dentro los RA, se encuentran los desechos de papa y yuca, los cuales no reciben actualmente un tratamiento para darles valor agregado. Una forma de valorizar estos residuos es a través del enriquecimiento proteico producto de la fermentación en estado sólido (FES). En este trabajo, empleando residuos de papa y yuca como fuente de carbono y energía, evaluamos la adición de dos fuentes de nitrógeno: sulfato de amonio (10 g/L) y peptona (10g/L) y dos niveles de humedad (10 y 30%) a través de un diseño de experimentos factorial 2 , con una duración de 24 días. La proteína fue medida por el método de Biuret, previa separación de la proteína del sustrato.Nuestro análisis estadístico indica que los efectos combinados fueron mejores que los simples: para la papa el más alto enriquecimiento proteico fue de 166,29 %, obtenido con la combinación de humedad del 30% y sulfato de amonio como fuente de nitrógeno. Para la yuca el más alto enriquecimiento proteico fue de 171,05 %, obtenido a un 10% de humedad y con peptona como fuente de nitrógeno.

Sheep wool protein hydrolysate: a new peptone source for microorganisms

AbstractBACKGROUNDPeptones are one of the most expensive components of microbial culture media. The present study was performed to produce microbial peptone from sheep wool using a new chemical process.RESULTSWool peptone (WP) was found to have high protein (67.8 g per 100 g) and ash (29.2 g per 100 g) contents. Glutamic acid was the most abundant amino acid in WP with a content of 8175 mg per 100 g). Wool peptone (WP) also had a high content (5042 mg per 100 g) of cystine, a sulphur‐containing amino acid. Optimal concentration of WP was determined as 5 g L−1 for the fungi and 6 g L−1 for the bacteria. Staphylococcus aureus showed very poor growth performance in WP medium. Growth performances of Saccharomyces cerevisiae, Bacillus subtilis and Penicillium chrysogenum were at moderate levels in WP medium. The best growth performance for Aspergillus niger was observed in WP medium with a biomass production of 8.17 g L−1. Second best growth performance for Escherichia coli was achieved with WP among the tested peptones.CONCLUSIONWool peptone (WP) was shown to be a good growth substrate, especially for A. niger and E. coli. This is the first investigation on use of wool as peptone source or substrate for microorganisms. © 2016 Society of Chemical Industry

Significant Effects Due to Peptone in Kelman Medium on Colony Characteristics and Virulence of Ralstonia solanacearum in Tomato

The study was taken up to assess if the media constituents played any role in governing the variable colony characteristics or pathogenicity of the bacterial wilt pathogen, Ralstonia solanacearum cultured on the widely employed Kelman medium. The effects due to the constituents 2,3,5-triphenyl tetrazolium chloride (TTC), peptone, casein hydrolysate and glucose on colony characteristics were investigated using -80°C stored culture of strain ‘NH-Av01’ (race 1, biovar 3) isolated from tomato. Comparing the pigment inducing TTC from two brands, its source or mode of storage/incorporation did not impart any significant effects. The source of peptone, on the other hand, displayed striking effects on the extent of colony growth, fluidity and red pigmentation depending on type, brand or batch / lot of manufacture as documented with 20 different formulations. Significant differences in the pathogenicity of isolate derived from different peptone sources in seedling-challenge assay on tomato were observed. The observations on peptone effects were endorsed with four other isolates belonging to distinct geographic locations, crops (eggplant, chilli, ginger) or races (race 1 or 4). The peptone source did not influence the pathogen-responses in biovar tests but notably altered the pattern of lawn formation and inhibition zone development during antagonistic assays. Casein hydrolysate displayed some variable effects while glucose source had no effect. This study brings to light the significant modifying effects by the peptone-constituent in Kelman medium on the physiology of R. solanacearum and the virulence of isolate and the need to consider the source of media components during culture maintenance, host-pathogen interaction studies or microbe-microbe interaction investigations.

Biological Degradation of Metribuzin and Profenofos by some Efficient Bacterial Isolates

The soil sample was collected from the paddy field of Sriperumbudur, Tamilnadu which is having a history of repeated pesticide applications. The isolation of efficient pesticide degrading bacteria was identified as Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis. The growth of the three pesticide degrading isolates was assessed in Minimal salt broth containing 25 ppm of pesticides. Two popularly used pesticides Metribuzin and Profenofos were selected for this study. Among the three bacterial isolates, the bacteria Bacillus subtilis utilized the pesticides effectively and showed maximum growth. The growth of the three pesticides degrading isolates Pseudomonas aeruginosa, Staphylococcus aureus and Bacillus subtilis was assessed in Minimal salt broth containing 25 ppm of pesticides at different temperature levels (25 °C, 30 °C, 35 °C, 40 °C, 45 °C, 50 °C &amp; 55 °C) and pH levels (pH 4, pH 5, pH 6, pH 7 &amp; pH 8) and carbon sources (Lactose, Dextrose, Fructose, Mannose &amp; Galactose) and nitrogen sources Peptone, Yeast extract, Beef extract, Malt extract and Casein respectively. The maximum growth rate of bacteria was recorded at 35 °C and pH 6. The maximum growth of bacteria was in the presence of Dextrose followed by Fructose, Galactose and Mannose. The least growth was recorded in Lactose broth culture. The maximum growth of bacteria was in the presence of Malt extract followed by Peptone, Yeast extract and Casein. The least growth was recorded in Beef extract broth culture. The bacterial isolates showed maximum growth in the Minimal salt broth containing Profenofos followed by Metribuzin