Development of a low-cost medium for production of nisin from Lactococcus lactis subsp. lactis

Abstract

The goal of this project was to develop a lowercost medium for nisin production, so this bacteriocin could be used in a broader range of industrial fermentation processes. The objectives included: (1) evaluating methods for controlling the inhibitory effect of lactic acid produced during fermentation, and (2) comparing two inexpensive complex media for nisin production. Lactococcus lactis subsp. lactis was cultured in shake flasks on LaurelTryptose broth to evaluate a range of buffers for pH control. NaHCO 3 proved to be an effective buffer for increasing nisin production. Subsequent trials then evaluated condensed corn soluble (CCS, a fuel ethanol production byproduct) and cheese whey as inexpensive growth media. CCS was shown to be an efficient, low-cost medium for high nisin titers and yields. These modifications reduced the medium costs for nisin production from $600/ kg nisin (based on Laurel-Tryptose broth medium) to $35-40/kg nisin for the corn solubles medium.

Production of nisin and lactic acid from corn stover through simultaneous saccharification and fermentation

“…lactis ATCC 11 454 in Wolf-Hall's work. The highest nisin titer of 795 IU/ mL was obtained in the medium of cheese whey with pH control [35]. Fermented barley extract obtained from a barley shochu by-product and its ethanol fractions have been evaluated as a medium for nisin production by Lactococcus lactis subsp.…”

Enhanced Bacteriocin Production by Pediococcus pentosaceus 147 in Co-culture With Lactobacillus plantarum LE27 on Cheese Whey Broth

“…Different studies have demonstrated that whey is an adequate substrate that supports the growth of Lactobacillus spp. strains as well as metabolite production, such as lactic acid (Panesar and Kennedy, 2011; Prazeres et al, 2012) or bacteriocins (Liu et al, 2005; Wolf-Hall et al, 2009; Garsa et al, 2014). Growth of P. pentosaceus 147 on the MRS and CW broths was very similar (Figure 2, right).…”

“…Different studies have focused on the design of a new medium due to the high cost of the MRS broth in order to reduce the cost of bacteriocins production (Guerra et al, 2001; Liu et al, 2005; Kumar et al, 2012; Kaur et al, 2013; Suganthi and Mohanasrinivasan, 2015; Hati et al, 2017). In the last decade, research on bacteriocin production has focused on the development of simpler (and lower cost) culture media obtained from different natural sources such as molasses, corn syrup (Todorov and Dicks, 2006a,b), soy milk (Wolf-Hall et al, 2009), and cheese whey (CW) (Liu et al, 2005; Kumar et al, 2012; Prazeres et al, 2012; Hati et al, 2017) in order to obtain high amounts of bacteriocins with minimal cost and minimal usage of industrial waste products. CW is a highly nutritional matrix, containing more than half of the solids present in milk, with 6–10 g/L of proteins, 46–52 g/L of lactose, and minerals (Conti et al, 2012).…”