Enhancement of alpha amylase production by Aspergillus flavus AUMC 11685 on mandarin (Citrus reticulata) peel using submerged fermentation

Mandarin peel as submerged fermentation (SmF) source was tested for the production of alpha amylase enzyme by strain of Aspergillus flavus AUMC 11685. Incubation period, concentration of substrate, temperature, pH and size of inoculum were optimized to achieve the maximum production of alpha amylase enzyme by Aspergillus flavus using mandarin peel. The maximum production of alpha amylase enzyme by Aspergillus flavus was recorded at 4-5 days of incubation, 3% substrate concentration, inoculum concentration 10%, temperature 28-40°C and pH 4-5.5. DOI: http://dx.doi.org/10.5281/zenodo.81827

Enhancement of Growth and Grain Yield of Rice in Nutrient Deficient Soils by Rice Probiotic Bacteria

Plant associated bacteria are promising alternatives to chemical fertilizers for plant growth and yield improvement in an eco-friendly manner. In this study, rice associated bacteria were isolated and assessed for mineral phosphate solubilizationand indole-3-acetic acid (IAA) production activity in vitro. Six promising strains, which were tentatively identified as phylotaxon Pseudochrobactrum sp. (BRRh-1), Burkholderia sp. (BRRh-2), Burkholderia sp. (BRRh-3), Burkholderia sp. (BRRh-4), Pseudomonas aeruginosa (BRRh-5 and BRRh-6) based on their 16S rRNA gene phylogeny, exhibited significant phosphate solubilizing activity in National Botanical Research Institute phosphate growth medium, and BRRh-4 displayed the highest phosphate solubilizing activity, followed by BRRh-5. The pH of the culture broth declined, resulting in increase of growth rate of bacteria at pH 7, which might be due to organic acid secretion by the strains. In presence of L-tryptophan, five isolates synthesized IAA and the maximum IAA was produced by BRRh-2, followed by BRRh-1. Application of two most efficient phosphate solubilizing isolates BRRh-4 and BRRh-5 by root dipping (colonization) of seedling and spraying at the flowering stage significantly enhanced the growth and grain yield of rice variety BRRI dhan-29. Interestingly, application of both strains with 50% of recommended nitrogen, phosphorus and potassium fertilizers produced equivalent or higher grain yield of rice compared to the control grown with full recommended fertilizer doses, which suggests that these strains may have the potential to be used as bioinoculants for sustainable rice production

Comparative molecular studies of halophilic bacteria from saline water and soil in the Saudi environment

Halophilic bacteria are a microorganism that grows optimally in the presence of the very high concentration of sodium chloride. Halophiles are vital sources of various enzymes including hydrolases, which are very stable and catalytically highly efficient at high salt concentration and other extreme conditions such as high temperature, pH and presence of organic solvents.  Several hydrolases such as amylases, proteases, and lipases have been obtained from halophilic bacteria and are commonly used for various industrial applications. We initiated a screening project to isolate and characterize the halophilic bacteria from the Red Sea, which is one of the saltiest bodies of water in the world. Water and soil samples, collected from the Red Sea coast, Jeddah, Saudi Arabia, were screened for isolation of halophilic bacteria. Ten bacterial isolates were obtained, which were characterized by biochemical tests and 16S rRNA gene sequencing. Hydrolase producing bacteria among the isolates were screened by plate assay on starch and gelatin agar plates for amylase and protease, respectively.  Two bacterial isolates i.e Bacillus haynesii and Enterobacter cloacae subsp. were found to possess significant amylase and protease activity. Further characterization of both the strains is in progress

Enhancement of alpha amylase production by Aspergillus flavus AUMC 11685 on mandarin (Citrus reticulata) peel using submerged fermentation

Mandarin peel as submerged fermentation (SmF) source was tested for the production of alpha amylase enzyme by strain of Aspergillus flavus AUMC 11685. Incubation period, concentration of substrate, temperature, pH and size of inoculum were optimized to achieve the maximum production of alpha amylase enzyme by Aspergillus flavus using mandarin peel. The maximum production of alpha amylase enzyme by Aspergillus flavus was recorded at 4-5 days of incubation, 3% substrate concentration, inoculum concentration 10%, temperature 28-40°C and pH 4-5.5. DOI: http://dx.doi.org/10.5281/zenodo.81827