Response surface methodology: An effective optimization strategy for enhanced production of nitrile hydratase (NHase) by Rhodococcus rhodochrous (RS-6)

Abstract

Nitrile hydratase is an enzyme which catalyze the hydration of nitriles into amide and their role as catalysts for acrylamide production in industries are well known. The present study aims at statistically optimizing physiological and nutritional parameters for NHase production from Rhodococcus rhodochrous (RS-6). The effect of incubation period, temperature, pH, carbon and nitrogen sources on the production of NHase was investigated by one factor at a time strategy. Further optimization process was carried out by response surface methodology for studying the interactive effect of these variables using central composite design. The optimized levels of variables obtained by statistical analysis were: incubation period 48 h, temperature 33 °C, pH 7.0, glycerol 1% and urea 0.75%, which resulted in maximum NHase production. The results of ANOVA were significant with the F -value of the model being 296.78, value of R 2 is 0.9983 and the lack of fit test was not significant. The contour and response surface plots showed significant interaction between the variables. The NHase yield was enhanced up to 6.22 fold by statistical optimization using RSM. Thus, the developed experimental design is effective towards process optimization for NHase production from R . rhodochrous (RS-6).

A new source of bacterial myrosinase isolated from endophytic Bacillus sp. NGB-B10, and its relevance in biological control activity

“…The application of RSM resulted in a myrosinase activity with a 10.03 increase higher than that obtained before optimization. Various reports documented that nitrogen source has a major effect on regulating bacterial growth and enzyme synthesis (Mefteh et al 2019 ; Sahu et al 2020 ). The incubation period is also a key parameter influencing the production of bacterial enzymes in culture media or submerged fermentation which is correlated to the reduction of nutrients available to the bacterial cells (Sahu et al 2020 ).…”

“…Various reports documented that nitrogen source has a major effect on regulating bacterial growth and enzyme synthesis (Mefteh et al 2019 ; Sahu et al 2020 ). The incubation period is also a key parameter influencing the production of bacterial enzymes in culture media or submerged fermentation which is correlated to the reduction of nutrients available to the bacterial cells (Sahu et al 2020 ). Furthermore, agitation speed plays an important role in promoting cell growth and thus enzymatic production which is most likely due to the high oxygen supply and nutrient transfer rate in the culture medium (Sai-Ut et al 2014 ).…”

Evaluation of acrylamide production by Rhodococcus rhodochrous (RS-6) cells immobilized in agar matrix

“…The soil isolate R. rhodochrous (RS‐6) was grown in 100 ml of M2 (minimal) medium (yeast extract: 0.3% malt extract: 0.3%, peptone: 0.5% and glycerol: 1%) (pH 7.0) with 1% substrate (acrylonitrile) under optimized conditions for 36 h (Sahu et al, 2020). After the incubation period, the cell pellets were obtained by centrifugation at 8000 g for 5 min and washed two times with KH 2 PO 4 buffer (0.1 M) and re‐suspended in the same buffer and used for immobilization studies.…”

“…Previously, we identified a soil isolate R. rhodochrous (RS‐6) with nitrile hydratase activity potential to convert acrylonitrile to acrylamide (Sahu et al, 2020). In the present study, we screened various substrates for immobilization for finding a suitable one for retaining the efficiency of conversion of acrylonitrile to acrylamide by R. rhodochrous (RS‐6).…”

Prospective Evaluation of an Amide-Based Zinc Scaffold as an Anti-Alzheimer Agent: In Vitro, In Vivo, and Computational Studies

“…Following the regression equation of slope, the nitrile levels were estimated as Y = 0.003432 X + 0.0366. 40 …”