The inhibitory effects of Lactobacillus casei and Lactobacillus helveticus on Bacillus species isolated from raw milk in various salt concentrations

Abstract

Nineteen strains of Bacillus were isolated and identified from 111 samples of raw milk. The inhibitory effects of Lactobacillus casei and Lactobacillus helveticus on strains of Bacillus were studied. The inhibitory effects were evaluated (using the well diffusion method) on nutrient agar, with NaCl added at concentrations of 40, 45, 50, 55, 60 and 65 g/L. Lactobacillus casei inhibited 16 strains of Bacillus on nutrient agar without salt, and 18 strains in the presence of salt. When the salt concentration was 6.5%, the inhibitory effect decreased, and L. casei inhibited only eight strains of Bacillus ( Bacillus cereus, Bacillus sphaericus, Bacillus licheniformis, Bacillus macerans, Bacillus firmus, Bacillus coagulans, Bacillus polymyxa and Bacillus stearothermophilus). Lactobacillus helveticus formed the inhibitory zones against five strains of Bacillus on nutrient agar without salt, but with 4% NaCl concentration, it showed an inhibitory effect on 13 strains; a further two strains were inhibited in the presence of 4.5 and 5.0% salt. In 5.5% NaCl, the same 15 strains were inhibited by L. helveticus, whilst in 6 and 6.5% salt, the inhibitory effect decreased and only six and seven strains were affected, respectively. The maximum inhibitory effect with both L. casei and L. helveticus was observed in the presence of 4.5–5.5% salt.

Effects of diets supplemented with either individual or combined probiotics,Bacillus subtilisE20 andLactobacillus plantarum7-40, on the immune response and disease resistance of the mud crab,Scylla paramamosain(Estampador)

“…Lactic acid bacteria are widely reported to be able to inhibit or kill food‐borne and other pathogenic microorganisms as well as simple spoilage bacteria, including Bacillus spp., by producing a variety of antimicrobial agents, such as organic acids (lactic and acetic acids), bacteriocins, diacetyl, carbon dioxide, hydrogen peroxide and ethanol (Adams & Nicolaides ; Helander, vonWright & MattilaSandholm ; Uraz et al . ; Røssland et al . ).…”

“…and Lactobacillus spp. (Uraz, Simsek & Maras ; Røssland et al . ; Vaseeharan & Ramasamy ; Domrongpokkaphan & Wanchaitanawong ; Olanrewaju ).…”

“…also has great antagonistic activity to wide range of bacteria by producing organic acids (Uraz et al . ; Røssland et al . ; Olanrewaju ).…”

Scientific Opinion on the maintenance of the list of QPS microorganisms intentionally added to food or feed (2009 update)

“…A few works described its presence in some foods, such as in raw milk (Uraz et al, 2001), during the processing and ripening of some cheeses (Roman-Blanco et al, 1999), or during cheese spoilage (Quiberoni et al 2008), although it was not described as a major component of the bacterial population of these foods. P. macerans is also described in the microflora of traditional fermented foods in Brasil (Almeida et al, 2007), Nigeria and in Asia (Isu and Njoku, 1997;Wang and Fung, 1996).…”

Atividade antimicrobiana de bactérias ácido-lácticas isoladas de queijos de coalho artesanal e industrial frente a microrganismos indicadores

“…Muitas BAL isoladas de leite e queijos apresentaram poder de inibição frente a patógenos e deteriorantes, como Staphylococcus spp., Listeria spp., Salmonella spp., Bacillus spp., Pseudomonas spp. e bactérias do grupo coliforme (Vaughan et al, 1994;Breashers e Durre, 1999;Uraz et al, 2001;Alexandre, 2002;Caridi, 2003). Esses trabalhos mostraram a importância do uso desses microrganismos para a preservação de alimentos e para o controle de patógenos.…”