No abstract

is a Gram positive anaerobic rod which belongs to the lactic acid bacteria (LAB) group. It is a facultative homo-fermenter found indigenous in dairy products such as Nono and cheese. Nono is a locally fermented milk beverage consumed in Nigeria. It is a functional food which contains high numbers of Lactic acid bacteria (LAB) which includes L. casei. It is usually enjoyed with a sorghum cake known as Fura and thus it is usually called Fura D'Nono. Despite its role as a functional food, unhygienic and unaseptic milking, processing, packaging and vending procedures, could render the food product susceptible to contamination with Escherichia coli and other enteric pathogens. Escherichia coli is one of the top seven pathogens of public health concern (CDC, 2014). E. coli O157:H7 is considered an emerging disease pathogen which causes infections such as hemorrhagic gastrointestinal disease and haemolytic uremic syndrome in humans (Isibor, et al., 2013). L. casei is well-known for its wide probiotic values such as bacteriocin production, bile tolerance, acid tolerance, ability to have a good attachment to the intestinal walls, immune modulation, cholesterol regulation, non-toxicity, antibacterial activity inter alia; and has been given Generally Recognized as Safe (GRAS) status, as there has not been any established risk to humans (Gaynor, 2012). Hence adopting it in food preservation comes with an added advantage when ingested along with the food it is meant to preserve, thus boosting the health status of the end food consumers. Biopreservation or bio-control is a measure employed as an alternative to the use of chemical preservatives and antibiotics for food preservation. Thus, this research aimed at the use of L. casei as a bio-control agent against E. coli proliferation in Nono.

Brewing is found to be one of the lucrative businesses in Nigeria. The brewer’s yeast commonly known as Saccharomyces cerevisiae is always imported and its  price affects the price of the products drastically. In this work, yeast strain was isolated from Palm Wine, identified as Saccharomyces cerevisiae and used as an alternative in beer brewing. The isolate (SPW) was seen to poses many similar characteristics of the brewer’s yeast (SCT) imported from foreign countries. The isolated and enriched yeast was employed in the laboratory for the production of beer. Results showed that both organisms failed to ferment melibiose and raffinose but fermented glucose, maltose, fructose, sucrose, and galactose. They survived at stress conditions for temperature and cell osmotic pressure in high concentration of ethanol and sugar. They showed good flocculation ability of 97%, and 82% respectively. Their percentage viability was 96.66% and 91.00% respectively with no production of hydrogen sulfide gas. The property of wort prepared for brewing was; pH of 5.82, specific gravity of 1.050 and iodine reaction showed yellow colour. After fermentation, the specific gravity was 1.001 and 1.010 for SPW and SCT respectively while alcohol content was 6.53% and 5.25% respectively. Wort was fermented at 28 ± 2oC for six days and the product beer showed apparent extract of 3.4oP and 4.8oP, Real extract of 4.8oP and 6.55oP, real degree of fermentation of 58.44% and 61.22% for SPW and SCT respectively.  Statistical analysis showed that yeast strain isolated from palm wine after enrichment had great potential when compared to brewer’s yeast strain in beer production attributes (p < 0·05).