Metabolic pathway analysis and dynamic macroscopic model development for lovastatin production by Monascus purpureus using metabolic footprinting concept

Morphological and structural characterization of chitin as a substrate for the screening, production, and molecular characterization of chitinase by Bacillus velezensis

The processing of shellfishery industrial wastes is gaining much interest in recent times due to the presence of valuable components. Chitin is one of the valuable components and is insoluble in most common solvents including water. In this study, a novel gram-positive bacterial strain capable of solubilizing chitin was screened from a prawn shell dumping yard. The chitinolytic activity of the isolated strain was observed through the zone of hydrolysis plate assay. The hyper-producing isolate was identified as Bacillus velezensis through the 16S rRNA sequencing technique. The structural and morphological characterization of raw and colloidal chitin preparation was carried out using FTIR, XRD, and SEM analysis. The residual protein and mineral content, degree of polymerization, and degree of acetylation were reported for both raw and colloidal chitin preparations. There was a linear increase in the chitinase activity with an increase in the colloidal chitin concentration. The maximum activity of chitinase was observed as 38.98 U/mL for the initial colloidal chitin concentration of 1.5%. Supplement of additional carbon sources, viz., glucose and maltose, did not improve the production of chitinase and resulted in a diauxic growth pattern. The maximum chitinase activity was observed to be 33.10 and 30.28 U/mL in the colloidal chitin-containing medium with and without glucose as a secondary carbon source, respectively. Interestingly, the addition of complex nitrogen sources has increased the production of chitinase. A 1.95- and 2.14-fold increase in the enzyme activity was observed with peptone and yeast extract, respectively. The chitinase was confirmed using SDS-PAGE, native PAGE, and zymograms. The optimum pH and temperature for chitinase enzyme activity were found to be 7.0 and 44 °C, respectively.

Effect of synthetic fatty liquor and neatsfoot oil as co-contaminants on the reduction of hexavalent chromium using Fusarium oxysporum and its kinetic study

The hexavalent chromium is one of the major carcinogenic components released during the tanning process and lots of work have been carried out on the reduction of hexavalent chromium via chemical and biological routes. Different fatty oils are also employed in the tanning process and have also been released as an effluent along with chromium. However, it is difficult to find a study on the reduction of chromium in the presence of other contaminant which would help to mimic the real-time complication of treating the tannery effluent. It is the first attempt on the reduction of hexavalent chromium in the presence of synthetic fatty liquor and neatsfoot oil using Fusarium oxysporum. The maximum percentage of chromium reduction was 73.62% and 60.28% in neatsfoot oil and synthetic fatty oil, respectively, for the initial chromium concentration of 25 mg/L. The biomass productivity was better with both neatsfoot oil and synthetic fatty oil, whereas the same has decreased with the presence of chromium. The reduction of chromium was found to follow the uncompetitive substrate inhibition kinetics than the general Michaelis-Menten kinetics. The kinetic parameters were calculated using particle swarm optimization algorithm, which were compared with the already reported data. The uncompetitive substrate inhibition kinetics was represented the experimental data in both the cases and the value of substrate inhibition constant was low in the case of neatsfoot oil compared with the synthetic fatty liquor.

Production of pigments by Monascus ruber CCT0302 in culture media containing maltose as substrate

The aim of this study was to show how maltose production residues can be used to obtain natural pigments by Monascus ruber CCT 3802 in solid and submerged cultures. The microbial growth and the colour and heat stability characteristics of the pigments produced in both solid and submerged media, with different maltose syrup concentrations, were determined. The results showed that the addition of maltose provided significant increases in the velocity of microbial growth and production of red pigments. The highest radial growth velocity of Monascus ruber (0.1053 mm h−1) was obtained when cultivated in a medium containing 5 g L−1 of maltose syrup, corresponding to a 71.7% increase in growth as compared to the growth velocity in the control medium. Using submerged fermentation, the culture medium containing 10 g L−1 of maltose syrup provided the greatest concentrations of red pigments (14.54 AU510nm g−1 dry biomass) with an intense dark red colour, showing that Monascus ruber CCT 3802 had the capacity to assimilate the substrate and produce pigments. The red pigments produced in the cultures showed good heat stability with activation energies of 13.735 Kcal mol−1.

Perspectives on Functional Red Mold Rice: Functional Ingredients, Production, and Application

Monacolin K (MK) is a secondary metabolite of the Monascus species that can inhibit cholesterol synthesis. Functional red mold rice (FRMR) is the fermentation product of Monascus spp., which is rich in MK. FRMR is usually employed to regulate serum cholesterol, especially for hypercholesterolemic patients who refuse statins or face statin intolerance. The present perspective summarized the bioactive components of FRMR and their functions. Subsequently, efficient strategies for FRMR production, future challenges of FRMR application, and possible directions were proposed. This perspective helps to understand the present situation and developmental prospects of FRMR.

Development of One Pot Strategy for Hyper Production and In Vivo Evaluation of Lovastatin

The aim of this project was to improve the Aspergillus terreus strain and pretreatment of sugarcane bagasse as carrier substrate for bulk production of lovastatin, a cholesterol-lowering drug, in solid state fermentation. Sugarcane bagasse was treated with alkali (1–3% NaOH) for the conversion of complex polysaccharides into simple sugars for better utilization of carrier substrate by microorganism for maximum lovastatin production. Ethidium bromide (time of exposure 30–180 min) was used to induce mutation in Aspergillus terreus and the best mutant was selected on the basis of inhibition zone appeared on petri plates. Fermented lovastatin was quantified by high-performance liquid chromatography. The fermented lovastatin, produced by parent and mutant Aspergillus terreus strain, was checked on body weight, blood glucose and serum cholesterol, ALT, AST, HDL-C, LDL-C, TG and TC levels of rats for their cholesterol lowering capacity. Our results indicate that selected strain along with 2% NaOH treated sugar cane bagasse was best suitable for bulk production of lovastatin by fermentation and fermented lovastatin effectively lower the cholesterol level of rats.