Value-Added Production of Nisin from Soy Whey

Abstract

The objective of this study was to evaluate the potential of low/negative value soy whey (SW) as an alternative, inexpensive fermentation substrate to culture Lactococcus lactis subsp. lactis for nisin production. Initially, a microtiter plate assay using a Bioscreen C Microbiology Plate Reader was used for rapid optimization of culture conditions. Various treatments were examined in efforts to optimize nisin production from SW, including different methods for SW sterilization, ultrasonication of soy flake slurries for possible nutrient release, comparison of diluted and undiluted SW, and supplementation of SW with nutrients. In subsequent flask-based experiments, dry bacterial mass and nisin yields obtained from SW were 2.18 g/L and 619 mg/L, respectively, as compared to 2.17 g/L and 672 mg/L from a complex medium, de Man-Rogosa-Sharpe broth. Ultrasonication of soybean flake slurries (10% solid content) in water prior to production of SW resulted in ∼2% increase in biomass yields and ∼1% decrease in nisin yields. Nutrient supplementation to SW resulted in ∼3% and ∼7% increase in cell and nisin yields, respectively. This proof-of-concept study demonstrates the potential for use of a low/negative value liquid waste stream from soybean processing for production of a high-value fermentation end product.

Production of Bioactive Peptides from Lactic Acid Bacteria: A Sustainable Approach for Healthier Foods

“…Also, cull potatoes, the unacceptable version of potato tubers, cannot support the growth of L. lactis alone, but as part of a supplemented media, the simultaneous production of bacteriocins and lactic acid was optimized (Liu, Liu, & Chen, ). Soy whey, a residue from the isolation of soy proteins, demonstrated to achieve higher yields in bacteriocin production compared to other dairy and nondiary supplemented media, even when it only contains 2.2% of protein (Mitra et al., ). ACE‐inhibitory activity was observed in bioactive peptides generated by the proteolytic strain Lactobacillus acidophilus in a supplemented soy whey media (Fung & Liong, ).…”

Soybean‐based concept biorefinery

“…used whey as a substrate for Lactobacillus plantarum , aiming to produce a potential fermented beverage from soy, with sanitary and nutritional improvements. Mitra et al 94 . studied the production of nisin, an antibacterial peptin produced by Lactococcus lactis .…”

Impact of Processing Condition on Nutraceutical Potency of Soy Whey Hydrolysate

“…Soy whey, one of the liquid by-products generated during tofu preparation, is becoming a point of concern for soybean processing industry. Mitra et al (2010) reported that production of soy protein isolate results in generation of soy whey (chemical oxygen demand [COD], 25,000 mg/L) equivalent to one-third of the initial raw material. Thus, a huge economic penalty is borne by the industry due to its disposal cost.…”

“…Mitra et al . () reported that production of soy protein isolate results in generation of soy whey (chemical oxygen demand [COD], 25,000 mg/L) equivalent to one‐third of the initial raw material. Thus, a huge economic penalty is borne by the industry due to its disposal cost.…”