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Background Selection of a microbial strain for the incorporation into food products requires in vitro and in vivo evaluations. A bacteriocin-producing lactic acid bacterium (LAB), Pediococcus acidilactici Kp10, isolated from a traditional dried curd was assessed in vitro for its beneficial properties as a potential probiotic and starter culture. The inhibitory spectra of the bacterial strain against different gram-positive and gram-negative bacteria, its cell surface hydrophobicity and resistance to phenol, its haemolytic, amylolytic and proteolytic activities, ability to produce acid and coagulate milk together with its enzymatic characteristics and adhesion property were all evaluated in vitro. Results P. acidilactici Kp10 was moderately tolerant to phenol and adhere to mammalian epithelial cells (Vero cells and ileal mucosal epithelium). The bacterium also exhibited antimicrobial activity against several gram-positive and gram-negative food-spoilage and food-borne pathogens such as Listeria monocytgenes ATCC 15313, Salmonella enterica ATCC 13311, Shigella sonnei ATCC 9290, Klebsiella oxytoca ATCC 13182, Enterobacter cloaca ATCC 35030 and Streptococcus pyogenes ATCC 12378. The absence of haemolytic activity and proteinase (trypsin) and the presence of a strong peptidase (leucine-arylamidase) and esterase-lipase (C4 and C8) were observed in this LAB strain. P. acidilactici Kp10 also produced acid, coagulated milk and has demonstrated proteolytic and amylolactic activities. Conclusion The properties exhibited by P. acidilactici Kp10 suggested its potential application as probiotic and starter culture in the food industry.

Lactic acid bacteria (LAB) are of major interest in the food industry primarily by virtue of their biopreservative properties. LAB have ability to produce various types of antimicrobial compounds, the most important being bacteriocins. Bacteriocins and bacteriocin-producing cultures have the potential to increase the shelf-life of foods and contribute towards decreasing the incidence of food-borne diseases. In this respect, food preservation through in situ production of bacteriocins by LAB introduced into the food system would be the most logical approach. However, there is a need to understand the relationship between bacterial growth and bacteriocin production in various types of food system. Bacteriocin production by LAB is dependent on a number of factors such as the types of carbon and nitrogen sources and their concentrations in the media formulation. Other factors which need to be considered are the culture conditions which include pH, temperature and aeration which greatly influence the cultivation performance of bacteriocins producing LAB. Economic aspects pertaining to the optimization of fermentation process for the enhancement of bacteriocin production should also be given due considerations. Failure to acknowledge or recognize this hidden economic element would be a substantial financial loss to the industry especially from the point of view that the product is costly and highly sought after. Thus, the fermentation factors which influence the production of bacteriocins by LAB and the approaches to improve the production not only in term of yield and productivity but also in term of economic and regulation are reviewed in this paper.

Monoclonal antibody (McAb) has been established as one of the most successful therapeutic strategies for the treatment of cancer. M1A2 (McAb) as a new monoclonal antibody was designed to recognize heat shock protein (HSP60), but its optimum production condition has not been studied. In this study, the cell culture conditions for both Roswell Park Memorial Institute Medium (RPMI 1640) and Dulbecco’s Modified Eagle Medium (DMEM) were optimized using artificial neural network (ANN) analysis to obtain maximum production of IgM McAb by hybridoma M1A2 cells. By using a central composite design, an experimental matrix with cultivation parameters of incubation time, temperature and fetal bovine serum (FBS) concentration on IgM McAb production was designed. The results was analysed by ANN network with different learning algorithms. From the analysis, batch back propagation (BBP) trained ANN composed of eight hidden nodes using a hyperbolic tangent sigmoid transfer function was capable to provide the highest McAb production for both RPMI and DMEM media. Under optimum conditions of 12.5% of FBS, at 33 °C after 3(1/2) days of incubation, maximum McAb production (1132.69 μg/ml) in DMEM was achieved. With PRMI 1640 medium, maximum McAb production (1105.12 μg/ml) was achieved at optimum conditions of 11% of FBS, at 33 °C after 4 days of incubation. The results of this study will provide information for optimum culture conditions of M1A2 McAb production in both DMEM and RPMI 1640 media and also give some clues for the other hybridoma excreting antibodies in the development of in vitro cell culture.

The microorganisms most commonly used as probiotics are lactic acid bacteria, especially those of the genus Lactobacillus. In the present study, two Lactobacillus strains, L. pentosus ITA23 and L. acidipiscis ITA44, previously isolated from mulberry silage, were characterized for their antiproliferative and antioxidant activities. The antiproliferative effects of the strains were investigated using the MTT assay with breast cancer (MDA-MB-231), liver cancer (HepG2) and normal liver (Chang) cell lines. The strains were tested for their antioxidant activity using the FRAP and ABTS methods. The results showed that the two Lactobacillus strains had good antiproliferative effects against both cancer cell lines tested, while their effects on the normal cells were weak. Based on the results of the antioxidant tests, the intact cells and cell-free extracts of the two Lactobacillus strains showed more than 135 and less than 50 µg trolox/ml of antioxidant activity, respectively. Lactobacillus pentosus ITA23 and L. acidipiscis ITA44 can be considered as potential probiotic candidates for humans because of their antioxidant activity and antiproliferation effects against cancer cells. Resumo Os micro-organismos mais comumente usados como probióticos são as bactérias lácticas, especialmente aquelas do genus Lactobacillus. No presente estudo, duas cepas de Lactobacillus, L. pentosus ITA23 e L. acidipiscis ITA44, previamente isoladas da silagem de amora, foram caracterizados por suas atividades antiproliferativas e antioxidantes. Os efeitos antiproliferativos das cepas foram investigados usando-se o ensaio MTT, com linhas de células cancerígenas de mama (MDA-MB-231) e do fígado (HepG2), e com células normais do fígado (Chang). As atividades antioxidantes das cepas foram testadas utilizando-se os métodos de FRAP e ABTS. Os resultados demonstraram que as duas cepas de Lactobacillus tinham bons efeitos antiproliferativos contra as duas linhas de células cancerígenas, enquanto seus efeitos nas células normais eram fracos. Baseando-se nos resultados dos testes antioxidantes, as células intactas e os extratos livres de células das duas cepas de Lactobacillus demonstraram mais que 135 e menos que 50 µg trolox/mL de atividade antioxidante, respectivamente. Lactobacillus pentosus ITA23 e Lactobacillus acidipiscis ITA44 podem ser considerados como potenciais candidatos probióticos para humanos, devido à sua atividade antioxidante e aos efeitos antiproliferativos contra células cancerígenas.

To investigate the prebiotic and immunomodulatory effects of PKC extract (OligoPKC) a total of 24 male rats were randomly assigned to three treatment groups receiving basal diet (control), basal diet containing 0.5% OligoPKC, or basal diet containing 1% OligoPKC for four weeks. We found that OligoPKC had no significant effect on the tested growth parameters. However, it increased the size of the total and beneficial bacterial populations while reducing pathogen populations. OligoPKC increased the concentration of immunoglobulins in the serum and cecal contents of rats. It also enhanced the antioxidant capacity of the liver while reducing lipid peroxidation in liver tissue. OligoPKC affected the expression of genes involved in immune system function in the intestine. Therefore, OligoPKC could be considered a potential mannan-based prebiotic for humans and animals due to its beneficial effects on the health and well-being of the model rats.