Significantly enhanced biomass production of a novel bio-therapeutic strain Lactobacillus plantarum (AS-14) by developing low cost media cultivation strategy

Abstract

BackgroundProbiotic bacteria are becoming an important tool for improving human health, controlling diseases and enhancing immune responses. The availability of a cost effective cultivation conditions has profound effect on the efficiency and role of probiotic bacteria. Therefore the current study was conducted with an objective to develop a low cost growth medium for enhancing the biomass production of a bio-therapeutic bacterial strain Lactobacillus plantarum AS-14. In this work the isolation of Lactobacillus plantarum AS-14 bacterial strain was carried out from brinjal using cheese whey as a main carbon source. Moreover, the effect of four other nutritional factors besides cheese whey was investigated on the enhanced cell mass production by using response surface methodology (RSM).ResultsThe best culture medium contained 60 g/l cheese whey, 15 g/l glucose and 15 g/l corn steep liquor in addition to other minor ingredients and it resulted in maximum dry cell mass (15.41 g/l). The second-order polynomial regression model determined that the maximum cell mass production (16.02 g/l) would be obtained at temperature 40°C and pH 6.2. Comparative studies showed that cultivation using cheese whey and corn steep liquor with other components of the selected medium generated higher biomass with lower cost than that of De Man, Rogosa and Sharpe (MRS) medium under similar cultivation conditions (pH 6.2 and temperature 40°C).ConclusionIt is evident that the cell biomass of L. Plantarum AS-14 was enhanced by low cost cultivation conditions. Moreover, corn steep liquor and ammonium bisulphate were perceived as low-cost nitrogen sources in combination with other components to substitute yeast extract. Of all these factors, cheese whey, corn steep liquor, yeast extract and two operating conditions (temperature and pH) were found to be the most significant parameters. Thus the cost effective medium developed in this research might be used for large-scale commercial application where economics is quite likely important.

Screening for efficient nitrogen sources for overproduction of the biomass of the functionally probiotic L. plantarum strain RPR42 in a cane molasses-based medium

“…Introduction of an optimized culture medium for biomass production of a given strain depends mainly on the physiological properties of the target strain. Considering the fact that the main probiotic genera are Bifidobacterium and Lactobacillus , an optimized medium for industrial cultivation of these bacteria could be expensive, requiring costly and complex supplements (peptones, beef extract, casein hydrolysate, and yeast extract) (Manzoor et al 2017). Furthermore, such microbes have unique physiological properties (Wee et al 2004) which caused their characteristic low growth yield.…”

“…The corn steep liquor (CSL), an agricultural by-product which is produced through the corn milling process, has been widely used as an economic nutrient-rich constituent of culture media in various large-scale bioprocesses (Manzoor et al 2017). CSL contains significant contents of amino acids, polypeptides and B-group vitamins and so, is a recommended nitrogen source for a diverse array of bioprocesses (Cardinal and Hedrick 1948).…”

“…Another nitrogen-rich agricultural by-product which has been widely used in biotechnology is cheese whey which is a main by-product of dairy industry. Cheese whey contains about 55% of the nutrients of the milk and is a recommended carbon source since it has a considerable lactose content (Manzoor et al 2017). This by-product also contains significant fractions of soluble proteins (0.6-0.8% w/v), lipids and minerals (Manzoor et al 2017).…”

“…Cheese whey contains about 55% of the nutrients of the milk and is a recommended carbon source since it has a considerable lactose content (Manzoor et al 2017). This by-product also contains significant fractions of soluble proteins (0.6-0.8% w/v), lipids and minerals (Manzoor et al 2017). Considering the aforementioned contents of the cheese whey, it can be also used as a whole culture medium for cultivation of some microbial species (Manzoor et al 2017;Okafor and Okeke 2017).…”

“…This by-product also contains significant fractions of soluble proteins (0.6-0.8% w/v), lipids and minerals (Manzoor et al 2017). Considering the aforementioned contents of the cheese whey, it can be also used as a whole culture medium for cultivation of some microbial species (Manzoor et al 2017;Okafor and Okeke 2017). Wheat germ extract (WGE), is another nutrient-rich substrate which can be regarded as a product of cereal agriculture.…”