• Journal of Life Science
• /
• v.30 no.12
• /
• pp.1128-1139
• /
• 2020

Over recent years, it has become evident that food and agricultural products are easily contaminated by fungi of Aspergillus, Fusarium, and Penicillium due to rapid climate change, which is not only a global food quality concern but also a serious health concern. Owing to consumers' interest in health, resistance to preservatives such as propionic acid and sorbic acid (which have been used in the past) is increasing, so it is necessary to develop a substitute from natural materials. In this review, the role of lactic acid bacteria as a biological method for controlling the growth and toxin production of fungi was examined. According to recent studies, lactic acid bacteria effectively inhibit the growth of fungi through various metabolites such as organic acids with low molecular weight, reuterin, proteinaceous compounds, hydroxy fatty acids, and phenol compounds. Lactic acid bacteria effectively reduced mycotoxin production by fungi via adsorption of mycotoxin with lactic acid bacteria cell surface components, degradation of fungal mycotoxin, and inhibition of mycotoxin production. Lactic acid bacteria could be regarded as a potential anti-fungal and anti-mycotoxigenic material in the prevention of fungal contamination of food and agricultural products because lactic acid bacteria produce various kinds of potent metabolic compounds with anti-fungal activities.

• Food Science and Industry
• /
• v.42 no.4
• /
• pp.27-35
• /
• 2009

• Asian-Australasian Journal of Animal Sciences
• /
• v.24 no.2
• /
• pp.250-257
• /
• 2011

An experiment was conducted to determine the effects of different mycotoxin adsorbents including esterified glucomannan (EGM), hydrated sodium calcium aluminosilicate (HSCAS) and compound mycotoxin adsorbent (CMA) on performance, blood parameters, and liver pathological changes in broilers fed mold-contaminated feed. Two hundred and forty 10-day-old broilers were randomly assigned to one of the five dietary treatments including: i) control diet; ii) mold-contaminated diet; iii) moldcontaminated diet+0.05% EGM; iv) mold-contaminated diet+0.2% HSCAS; v) mold-contaminated diet+0.1% CMA. At 35-days-old, blood and liver tissue samples were collected for analysis. 0.1% CMA improved ADG and ADFI during 10-42 d compared to the moldcontaminated group (p<0.05). The mold-contaminated diet increased total white blood cell (WBC) number, haemoglobin (Hgb) concentration, hematocrit (Hct) level, serum aspartate aminotransferase (AST) and ${\gamma}$-glutamyl transferase (GGT) activities, and decreased red blood cell (RBC) number and serum globulin (GLB) and urea nitrogen (BUN) concentrations (p<0.05). The three mycotoxin adsorbents alleviated the alteration of RBC, WBC, Hgb and AST caused by the mold-contaminated diet. Furthermore, 0.1% CMA increased GLB concentration and decreased Hct level and GGT activity (p<0.05). Liver superoxide dismutase (SOD) activity was reduced, and myeloperoxidase (MPO) activity was increased by the mold-contaminated diet (p<0.05). Both EGM and HSCAS prevented the increase of MPO activity (p<0.05). Liver lesion, including severe vacuolar degeneration of hepatocytes, was observed in chicks fed the mold-contaminated diet. 0.05% EGM prevented these effects except for biliary hyperplasia and mild vacuolar degeneration. 0.2% HSCAS showed medium vacuolar degeneration of hepatocytes. Liver of broilers fed 0.1% CMA revealed a mild vacuolar degeneration. These results indicate that a mold-contaminated diet results in adverse effects on blood parameters and liver morphology. 0.05% EGM and 0.2% HSCAS partially alleviated the adverse effects. However, 0.1% CMA almost completely ameliorated the adverse effects.

• Mycobiology
• /
• v.42 no.3
• /
• pp.291-295
• /
• 2014

Mycoflora was assessed in the commercial meju from four well-separated geographic origins. A total of 112 fungal isolates were identified by phenotypic characteristics and molecular taxonomy using sequencing the internal transcribed spacer of the rDNA and revealed 19 species from 13 genera. Enzymatic characteristics of protease and amylase, and mycotoxin production were analyzed.

• Journal of Microbiology and Biotechnology
• /
• v.12 no.4
• /
• pp.679-682
• /
• 2002

The alkaloids, piperlongumine, piperine, pipernonaline, and piperoctadecalidine, isolated from Piper longum L., were found to inhibit the biosynthesis of aflatoxin $B_1$ (AF$B_1$) in Aspergillus flavus WRRC 3-90-42-12. Piperlongumine was the most active among the compounds tested, with a 96% inhibition of AF$B_1$biosynthesis at 0.2% (w/v) supplement in a potato dextrose agar (PDA) medium. The three other piperidine alkaloids, pipeline, pipernonaline, and piperoctadecalidine, also inhibited the biosynthesis of AF$B_1$. Of these three alkaloids, piperoctadecalidine exhibited a potent inhibitory activity with a 100% inhibition of AF$B_1$ production at 0.7% (w/v) supplement in a PDA medium. Therefore, piperlongumine and piperoctadecalidine could be used as antiaflatoxigenic agents in agricultural industries. To determine the antiaflatoxigenic mode of action of piperlongumine, further studies are needed.

• Proceedings of the Korean Society of Plant Pathology Conference
• /
• 2003.10a
• /
• pp.85.2-86
• /
• 2003

Fusarium graminearum is an important pathogen of cereal crops in many areas of the world causing head blight and ear rot of small grains. In addition to serious economic losses, this fungus produces mycotoxins, such as trichothecenes and zearalenone on diseased crops and has been a potential threat to human and animal health. To massively identify pathogenesis-related genes from F. graminearum, two representative strains (SCKO4 from rice and Z03643 from wheat) were mutagenized using restriction enzyme-mediated integration (REMI). In total, 20,DOD REMI transformants have been collected from the two strains. So far, 63 mutants for several traits involved in disease development such as virulence, mycotoxin production, and sporulation have been selected from 3,000 REMI transformants. Now, selected mutants of interest have being genetically analyzed using a newly developed outcross method (See Jungkwan Lee et al poster). In addition, cloning and characterization of genomic DNA regions flanking the insertional site in the genome of the mutants are in progress.

• Interdisciplinary Bio Central
• /
• v.2 no.4
• /
• pp.10.1-10.5
• /
• 2010

Total aflatoxin and ochratoxin were detected in 3 naturally contaminated fish feed samples using immune-affinity method. The results revealed that the average levels of aflatoxins in the 3 examined samples were (15, 22 and $12\;{\mu}g/kg$) respectively while the average levels of ochratoxins were (15, 6 and $6\;{\mu}g/kg$). The results of determination of the effects of clay as a mycotoxin binder on the health status and performance of Oreochromis niloticus in comparing with a control group revealed that the survival rate in control group was 81% after the end of the culture season. The results also revealed that the survival rate in group 2 which received clay treated feed was 86%. The results of regular parasitological examination revealed the identification of trichodina as external protozoa in Oreochromis niloticus from both ponds but without manifestation of disease signs. The results of bacteriological examination revealed the isolation and identification of Pseudomonas flouresence from some moribund Oreochromis niloticus. Higher performance parameters were recorded in group 2 that received feeds treated with clay which reflected in the total production which reaches 1646.47 kg while in the control pond, the total production was1308.36 kg.

• Journal of Food Hygiene and Safety
• /
• v.37 no.1
• /
• pp.9-14
• /
• 2022

The purpose of this study was to analyze the hazard of fungi in Garaetteok (Korean rice cake) by isolating and identifying of fungi contaminated with Garaetteok and investigating the possibility of mycotoxin production. Garaetteok used in this study were the ones that were returned back to the manufacturers in Jeollanam-do due to the presence of foreign matters presumed to be fungi. The fungi foreign matter was collected and inoculated on Potato dextrose agar, Malt extract agar, and Czapek yeast extract agar, and then cultured at 25℃ for 7 days. The micro-structure was observed under an optical microscope for the colonies in which pure isolation was confirmed. The gene sequencing of the product of amplified PCR was analyzed using the ITS primer. Colony-1 and 2 maintained the same properties in each tray, confirming that they were purely isolated. Budding cells were observed from the Colony-1, thus, it was determined to be yeast. Colony-2 was determined to be a fungus that belongs to Fusarium spp. as fusiform conidia were observed. As a result of gene sequencing, a total of 76 cases of fungi of Fusarium spp. were found, among which Fusarium solani was the most observed cases (53 cases). From the morphological and genetic identification, Colony-2 was identified as Fusarium spp., specifically, Fusarium solani. The fungi found in Fusarium spp. produce mycotoxins such as nivalenol, zearalenone, and fumonisin, which may cause vomiting, diarrhea, and cancer. Conclusively, the results confirm the possibility of mycotoxin production by Fusarium spp. isolated from Garaetteok. Consequently, when an unknown fungus was found, it is necessary to isolate and identify the fungus, determine whether it is a mycotoxin producing species, and strengthen relative administrative measures, accordingly.

• Journal of Life Science
• /
• v.19 no.1
• /
• pp.65-74
• /
• 2009

The objective of this study was to examine the effects of steam flaking treatment of corn grains imported from USA and India on in vitro gas production, microbial growth and contents of aflatoxin $B_1$ and ochratoxin A. Each treatment was composed of total 4 treatments including (1) USCW (US com-whole type), (2) USCF (US corn-flaked type), (3) IDCW (India corn-whole type) and (4) IDCF (India orn-flaked type) with 4 replications $\times$ 6 incubation times (3, 6, 9, 12, 18 and 24 hr). Mycotoxin (aflatoxin $B_1$ & ochratoxin A) contents in test corns tended to increase gradually with increasing logistics periods from the harbor, hopper, silo to processing line. The contents of aflatoxin $B_1$ in India corn (IDCW) and US corn (USCW) were 11.71 and 1.78 ppb, respectively when measured at the hopper. After steam flaking, both contents of aflatoxin $B_1$ in USCW and IDCW were 0.00 ppb. It means that Aspergillus flavus could be decreased by steam flaking. However, this trend was not observed in ochratoxin content. The gas production rate of USA corns (USCW & USCF) was significantly (p<0.05) higher than India corns (IDCW & IDCF), and that of steam flaked corns (USCF & IDCF) was higher $1.5{\sim}2%$ than whole corns (USCW & IDCW) after 3 hr incubation in in vitro experiment. pH value was optimally maintained for microbial growth during whole incubation times with the value of 6.05 to 6.54, and was not significantly different between treatments, but USCF was somewhat lower than other treatments. pH value decreased following 12 hr of incubation but gas production increased rapidly during the same period. In addition, in vitro microbial growth rates also increased with up to 18 hr of incubation period, thereafter experienced a decrease with extended incubation time. In conclusion, US corn was superior to India corn by origin based on the results of in vitro and mycotoxin contents. And steam flaking process of imported corns tended to decrease mycotoxin contents such as aflatoxin $B_1$ and ochratoxin A as well as improve in vitro gas production and microbial growth rates.

• Microbiology and Biotechnology Letters
• /
• v.24 no.2
• /
• pp.227-233
• /
• 1996

Tyrosinase is an enzyme which catalyzes an enzymatic browning of some foods and in vivo synthesis of melanin. In order to produce natural and edible inhibitor of the enzyme which is expected to have whitening effect on melanogenesis, a microorganism was selected from fermented foods. It was named as NU-7, and cultured in mushroom (Lentinus edodes, Shiitake) media. Optimal media to produce tyrosinase inhibitor was formulated by varing nitrogen or carbon content. If glucose content was in a range of 3-20% and ammonium sulfate was in a range of 0-0.25%, production of inhibitor was independent of cell mass. Addition of ammonium sulfate as a nitrogen source had little effect on inhibitor production. Production of inhibitor (Y) was proportionally related to shiitake content (X) with a regression equation of Y= -0.96X$^{2}$ + 13.07X + 14.43 (R = 0.96). These results indicate that shiitake and glucose are necessary for the production of tyrosinase inhibitor. In the analysis of mycotoxin in culture broth, aflatoxin was not detected, suggesting that it would be probably edible.