Detoxification of aflatoxin B1 by bacteriocins and bacteriocinogenic lactic acid bacteria

Abstract

IntroductionAflatoxins are secondary metabolites produced by molds that have carcinogenic, mutagenic, and teratogenic effects on humans and animals (1-3). Among the aflatoxins, aflatoxin B 1 (AFB 1 ) is one of the strongest known hepatocarcinogens and is classified as a category 1A carcinogen by the International Agency for Research on Cancer (4). Due to their importance in showing these effects in the consumption of contaminated foods, there is a serious effort made by the food industry to make products safe. Moreover, considering the tendency of consumers to prefer natural products because of the worry about possibly hazardous food additives, both researchers and producers are taking responsibility to investigate new ways as an answer to the consumer expectations.Although the different methods used at present are to some extent successful, they have major disadvantages with limited efficacy, possible losses of important nutrients, and normally high costs. Many workers in the field are of the opinion that the best solution for decontamination should be detoxification by biodegradation, giving a possibility for removal of mycotoxins under mild conditions without using harmful chemicals and without significant losses in nutritive value and palatability of decontaminated food and feed (5). A number of studies have found that some microorganisms, especially lactic acid bacteria, break down or bind to aflatoxins. Researchers have obtained different results in these studies conducted to investigate the in vitro aflatoxin binding/degradation effect of lactic acid bacteria (6-9). Zinedine et al. (10) indicated that the toxin binding level changes in some environmental conditions having different pH and temperature. Supporting this finding, Haskard et al. ( 7) also found that environmental conditions, acid and heating applications, and the structure of the bacteria had an important effect on the stability of the toxin-bacteria complex. In another study, Kabak (11) showed that the aflatoxin B 1 binding capability of probiotic lactic acid bacteria varied in vitro, and in food had 32%-46.5% of the in vitro toxin binding rate. Fuchs et al. (12) found that the effectiveness of lactic acid bacteria in detoxifying ochratoxin and patulin was affected by toxin concentration, cell density, pH of the environment, and whether the cells were viable. Based on these and similar results, Hernandez-Mendoza et al. (13) suggested that lactic acid bacteria bound the toxins to different extents depending on the environment and the amount of bile salt present.Another challenge for researchers is achieving the same good results when lactic acid bacteria are applied to food. First of all, certain temperatures and pH levels must be provided; otherwise, the microorganisms would not show their effects. Probably, a higher number of bacteria would

Removal of aflatoxin G1 using lactic acid bacteria

“…In a similar manner, Sezer et al., 2013 found that AFB1 authoritative by L. plantarum and L. lactis was practically finished in the initial 6 hr. Hussein (2008) watched an expansion in AFM1 official by L. casei and L. acidophilus inside the initial 60 hr of brooding followed by a steady restricting rate for the following 20 hr.…”

“…The pulverization of explicit parts of the bacterial cell divider, e.g., starches and proteins, brought about decrease in AFG1 authoritative by L. rhamnosus (Hernandez-Mendoza et al, 2009). It is likely, In a similar manner, Sezer et al, 2013 found that AFB1 authoritative by L. plantarum and L. lactis was practically finished in the initial 6 hr. Hussein (2008) watched an expansion in AFM1 official by L. casei and L. acidophilus inside the initial 60 hr of brooding followed by a steady restricting rate for the following 20 hr.…”

The efficiency of lactic acid bacteria against pathogenic fungi and mycotoxins

“…It was also found that the binding efficiency increased with time. Sezer et al (116) investigated the efficiency of LAB (L. lactis and L. plantarum) and their bacteriocins in removing AFB 1 from liquid culture. L. plantarum was more efficient than L. lactis (46 % vs 27 %, respectively), but efficacy was even higher when combined with bacteriocins.…”

Efficiency of Selected Lactic Acid Bacteria Isolated from some Dairy Products on Aflatoxin B1 and Ochratoxin A

“…Where it overlaps between the toxins and the functional groups of the cell surface happens, adsorption occurs. A lot of factors like temperature, pH, time of incubation, bacterial concentration and type of strain may affect the ability of LAB to bind toxins 8,9 . Therefore, this study aimed to evaluate the ability of some strains LAB, isolated from dairy products, to reduce or degrade AFB 1 and OTA from liquid media at (6h, 12h and 36 h) period incubation.…”