Optimization Of Carbon Sources For Maximal Production Of Lovastatin By Forest Soil Fungal Isolates Under Liquid State Fermentation (LSF)

Abstract

Most fungal secondary metabolites are remarkably complex bioactive compounds. Soil Fungi produce a large variety of compounds mainly through the polyketide biosynthesis pathway. Lovastatin is a fungal secondary metabolite used for lowering blood cholesterol. It acts as an effective inhibitor of the enzyme hydroxymethylglutaryl, coenzyme A (HMG-CoA), reductase (mevalonate: NADP1 oxydoreductase, EC 1.1.1.34) that catalyzes the reduction of HMG-CoA to mevalonate during synthesis of cholesterol. The main objective of the study is screening of various fungal species and optimization of different carbohydrate sources for maximizing lovastatin production by Aspergillus spp using Liquid State Fermentation (LSF). The soil samples were collected on the random basis from different locations around Pachmarhi, Madhya Pradesh (India). The pure cultures of these fungal isolates were screened for production of statin or lovastatin were evaluated by yeast inhibition test. Potential species were subjected to in vitro carbohydrates optimization in LSF fermentation and concentration of Lovastatin was estimated by HPLC. The pure culture of indigenous fungal isolated were screened for their capability of producing statin or lovastatin like substances was evaluated by adopting yeast inhibition model. For this ATCC culture of Candida albicans and Saccharomyces cerevisiae were used as model organism against which statin screening fungal isolates that showed antagonistic activity. Fungal isolate were subjected to in vitro production of lovastatin under the influence of different carbohydrate sources at a concentration of 30gm per litre in LSF medium. The quantity of lovastatin produced by Aspergillus spp using HPLC was found to be 1.48, 0.94, 8.19, 1.69, 0.07, percentage using Sucrose, Dextrose, Mannitol, Lactose and Maltose as source of carbohydrate respectively. Production of lovastatin was maximum using mannitol as a source of carbohydrate.