Role of amino acids in halotolerant Aspergillus repens

Attempts have been made earlier to understand the mechanisms of osmoregulation and the ability ot adapt to fluctuations in the external osmolarity (Ben-Amotz and Avron 1983. Ann. Rev. Microbiol. 37:95-119, Csonka 1989. Microbiol. Rev. 53:121-147). Various strategies have been adopted by the cells in order to survive and proliferate in the presence of reduced water activity, including accumulation of carbohydrates. amino acids and quaternary ammonium compounds (Measures 1975. Nature 257:398-400, Brown et al. 1972. J. Gen. Microbiol. 72:589-591, Dannibier et al. 1988. Arch. Microbiol. 150:348-357). In the present study, attempts were made to investigate the role of amino acids that accumulate intracellularly in halotolerant Aspergillus repens under salt stress condition

Phosphate mediated changes in phospholipids in Neurospora crassa.

Phosphate mediated changes in phospholipids in Neurospora crassa

Regulation of glucose-6-phosphate dehydrogenase under salt-stress condition in Aspergillus sydowii.

Physiological responses of organisms to particular stresses are well understood in only a few cases (Bachofen, R. 1986 Experientia 42:1179-1182

Phosphate mediated changes in fatty acid composition in Neurospora crassa.

Phosphate mediated changes in fatty acid composition in Neurospora crassa

Calcium effects in Neurospora crassa

Calcium effects in N. crass

Phosphate mediated regulation of carbohydrate metabolism in Neurospora crassa

Phosphate mediated regulation of carbohydrate metabolism in Neurospora crass

Full Length Research Paper - Activity staining method of chitinase on chitin agar plate through polyacrylamide gel electrophoresis

A method for detection of chitinase activity on chitin agar plate after polyacrylamide gel electrophoresis is described. Different staining dyes such as calcofluor white M2R, fluorescein isothiocyanate, rhodamine B, ruthenium red and congo red were separately incorporated in chitin agar plates. After running polyacrylamide gel electrophoresis, the gel was transferred onto chitin agar plate containing different dyes for the activity staining. Thin layer of acetate buffer (0.2 M, pH 5) was pored on the gel, which helps faster diffusion of the enzyme from gel onto the plate. After incubation of about 7 h, bands of chitinase were visible by daylight or UV light. The method is very sensitive since it can detect even 0.5 units of chitinase. Thus, this method is sensitive, rapid, user-friendly, reliable and cost effective

Formulation of medium constituents by multiresponse analysis of central composite design to enhance chitinase production in <i>Pantoea dispersa</i>

1123-1131In the present study, a high chitinase producing strain Pantoea dispersa was isolated from the sea dumps at Bhavnagar, India. Chitin, urea, CaCl2 and MgSO4.7H2O were variables used in central composite design for chitinase production. Chitinase, biomass and pH were the responses used in different models to evaluate individually fit ones. Quadratic model was found to be fit for chitinase response whereas in the case of biomass and pH, linear model was found to be fit without the effect of others. Chitinase production was optimized with respect to other responses such as biomass and pH in multiresponse analysis of response surface design by using desirability approach. In multiresponse analysis, following medium formulation (g/l), chitin, 15; urea, 0.32; CaCl2, 0.10 and MgSO4.7H2O, 0.08 was found to predict optimum chitinase production of 482.77 units/ml with overall highest desirability of 0.854 as compared to other formulation s. The selection of model was done on the basis of hi gh Adjusted R-squared value and lowered p-value for each model in individual analysis of each response. In multiresponse experiment, it was found that for response chitinase quadratic model and for responses pH and biomass linear models were well fit. Through desirability analysis, it was found that in the chitinase production, pH was essential as compared to biomass in P. dispersa. Endochitinase and chitobiase actvities were also studied

Isolation and identification of marine chitinolytic bacteria and their potential in antifungal biocontrol

715-720Chitinolytic marine bacterial strains (30) were isolated from the sea dumps at Bhavnagar, India. They were screened as chitinase producers on the basis of zone of clearance on chitin agar plates incorporated with calcofluor white M2R for the better resolution. Out of these, three strains namely, Pseudomonas sp., Pantoea dispersa and Enterobacter amnigenus showed high chitinase production. They were also found to produce proteases and therefore have a good potential for use as antifungal biocontrol agents for the control of fungal plant pathogens. These strains could degrade and utilize the mycelia of Macrophomina phaseolina (Tassi) Goidanich and Fusarium sp. In vitro, these strains could inhibit the growth of Fusarium sp. and M. phaseolina. The culture filtrate inhibiting hyphal elongation was observed microscopically

Review - Bioprospecting and antifungal potential of chitinolytic microorganisms

Fungal plant diseases are one of the major concerns to agricultural food production world wide. Soil borne pathogenic fungi such as Pythium, Fusarium, Rhizoctonia and Phytopthora attack most of the economically important crop plants (either through seed root before germination or seedling after germination) resulting in loss of billions of dollars. Moreover, the management of chitinous waste is also pressing need today. Mycolytic enzymes (chitinases, proteases and glucanase) producing microorganisms may help in solving these problems. These microorganisms have ability to lyse the fungal cell wall and also have the potential to manage the chitinous waste by producing chitinases. Many chitinolytic microorganisms have potential to control fungal plant pathogens but they are not fully successful in all the cases due to different geological and environmental conditions. Thus, bioprospecting to find novel, highly chitinolytic microorganisms which help in developing potential biocontrol agent. Furthermore, to increase the survivability of biocontrol agents, a formulation may also be necessary. This review is focused on the progress of chitinase genes, chitinolytic microorganisms and their diversity as well as formulation of chitinolytic producers which have the potential to control fungal plant pathogen