Review: Prevention and Reduction of Mycotoxin by Antagonistic Microorganism

Mycotoxin is widely known as one cause of foodborne disease, produced by toxigenic fungi. Any country should be aware about this high risk potency by knowing the mycotoxin, affected commodities, fungal sources, and toxicity effect to human or animal. Controlling mycotoxin could be done by physic, chemical, and biological methods. The microbial characteristic used for biological agent should be evaluated including the inability to produce toxic substance, tendency to multiply, colonize, survive, safety, and applicability to the environment. Studies related to mycotoxin biocontrol by using antagonistic microorganism can be focused on (1) the effect to the mycotoxin, (2) the growth of microorganism, or (3) the application to food both raw material and processed products. Consideration to combine more than one species of microorganism instead of a single species also has been taken to achieve more effective result. For example, S. cerevisiae has been used together with LAB to control certain mycotoxin. Further studies are needed to develop the possibility of other biological agents and the effect of their application, which in the next have the potency as manufacturing products.

Study on Soil Microbial Characteristics of Elsholtzia harchowensis in Copper Mine

In this paper, soil microbial characteristic of Elsholtzia harchowensis in copper mine were reported. The results indicated that metal element contents of Elsholtzia harchowensis were: Cu>Zn>Pb>Cd. There were significant correlations in Cu contents between Elsholtzia harchowensis and soil in copper mined tailings region. The Elsholtzia harchowensis possessed obviously different soil microbial features. The intensiver in microbial basal respiration strength, and higher microbial ecophysiological parameters, but lower in soil microbial biomass. The results showed that soil microbial community structure was obviously changed in the Elsholtzia harchowensis system, and much more consumed rapidly carbon sources, but the lower in the ratio of utilization compared with the control test.

Changes of microbial characteristics of retained sludge during low-temperature operation of an EGSB reactor for low-strength wastewater treatment

In this study, a lab scale EGSB reactor was operated for 400 days to investigate the influence of temperature-decrease on the microbial characteristic of retained sludge. The EGSB reactor was started-up at 15°C seeding with 20°C-grown granular sludge. The influent COD of synthetic wastewater was set at 0.6–0.8 gCOD/L. The process-temperature was stepwise reduced from 15°C to 5°C during 400 days operation. Decrease of temperature of the reactor from 15°C to 10°C caused the decline of COD removal efficiency. However, continuous operation of the EGSB reactor led the efficient treatment of wastewater (70% of COD removal, 50% of methane recovery) at 10°C. We confirmed that the both acetate-fed and hydrogen-fed methanogenic activities of retained sludge clearly increased under 15 to 20°C. Changes of microbial profiles of methanogenic bacteria were analyzed by 16S rDNA-targeted DGGE analysis and cloning. It shows that genus Methanospirillum as hydrogen-utilizing methanogen proliferated due to low temperature operation of the reactor. On the other hand, genus Methanosaeta presented in abundance as acetoclastic-methanogen throughout the experiment.