Statistical optimization of α-amylase production by Bacillus brevis MTCC 7521 in solid-state fermentation using cassava bagasse

Optimization of thermostable amylolytic enzyme production from Bacillus cereus isolated from a recreational warm spring via Box Behnken design and response surface methodology

This study aimed to find a source for local amylase-producing microbes. Sixteen isolates were obtained from the water samples from the warm spring and characterized based on morphological and biochemical tests. The 16S rRNA molecular identification technique confirmed the most potent isolate as Bacillus cereus. The thermophilic property of the bacterium demonstrated that it could withstand temperatures of up to 80 °C. One-factor-at-a-time (OFAT) and Box Behnken Design (BBD) coupled with response surface methodology (RSM) optimization techniques were used to improve amylase production. OFAT established optimal physical parameter conditions as the starch concentration of 5% w/v, inoculum volume of 2% v/v, pH of 8, incubation temperature of 45 °C, and 48 h of incubation, leading to amylase activity of 172.6 U/mL by the isolated B. cereus. A quadratic mathematical model with a coefficient of determination (R2) of 0.9957 was established for the amylase production process. Enhanced amylase activity of 196.02 U/mL was achieved with BBD-RSM under optimal growth conditions of pH of 7, incubation time of 48 h, substrate concentration of 5% w/v of starch, and at 45 °C, a 1.2-fold increase compared to the OFAT method. The B. cereus strain isolated from the warm spring was a mildly thermophilic bacterium with the potential for synthesizing amylolytic enzymes with characteristics beneficial for commercial utilization.

The Goldilocks Approach: A Review of Employing Design of Experiments in Prokaryotic Recombinant Protein Production

The production of high yields of soluble recombinant protein is one of the main objectives of protein biotechnology. Several factors, such as expression system, vector, host, media composition and induction conditions can influence recombinant protein yield. Identifying the most important factors for optimum protein expression may involve significant investment of time and considerable cost. To address this problem, statistical models such as Design of Experiments (DoE) have been used to optimise recombinant protein production. This review examines the application of DoE in the production of recombinant proteins in prokaryotic expression systems with specific emphasis on media composition and culture conditions. The review examines the most commonly used DoE screening and optimisation designs. It provides examples of DoE applied to optimisation of media and culture conditions.

Improving Bread Quality with the Application of a Newly Purified Thermostable α-Amylase from Rhizopus oryzae FSIS4

A new thermostable α-amylase from Rhizopus oryzae FSIS4 was purified for first time and recovered in a single step using a three-phase partitioning (TPP) system. The fungal α-amylase, at a concentration of 1.936 U per kg of flour, was used in bread-making and compared to the commercial enzyme. The results showed a significant effect of the recovered α-amylase in the prepared bread and allowed us to improve the quality of the bread. The study indicated clearly that the recovered α-amylase is a potential candidate for future applications in the bread-making industry and in other food biotechnology applications.

Heterotrophic cultivation of Nannochloropsis salina for enhancing biomass and lipid production

Response surface methodology (RSM) was used to enhance the biomass and lipid content in Nannochloropsis salina due to its economic importance. Preliminary screening results revealed that the heterotrophically cultivated N. salina with various carbon and nitrogen sources yielded higher biomass (0.91 ± 0.0035 g/L) and lipid content (37.1 ± 0.49 mg/L) than that of the photoautotrophical cultivation (0.21 ± 0.009 g/L and 22.16 ± 0.27 mg/L). Significant sources that greatly influenced on biomass and lipid content of the alga were optimized through RSM. The medium consisting of glucose (7.959 g/L), sodium acetate (1.46 g/L), peptone (7.6 g/L) and sodium thiosulphate (1.05 g/L) was found to be the optimal concentration for heterotrophic cultivation by response optimizer. Confirmation experiment results for the RSM optimized concentration yielded the biomass of 1.85 g/L and total lipid content of 48.6 mg/L. In this study, we provide with a strategy for enhancing the biomass and lipid content in N. salina.