• Journal of Microbiology and Biotechnology
• /
• v.24 no.8
• /
• pp.1088-1095
• /
• 2014

A systematic investigation was performed on the bacterial, Bacillus, fungal, and yeast communities of the three types of Daqu (mechanically prepared, manually prepared, and mixed prepared) used in Baiyunbian Company by reconditioning PCR-denaturing gradient gel electrophoresis (PCR-DGGE). The DGGE results showed that the microbes in the three types of Daqu were mainly thermotolerant and thermophilic microbes, and the most dominant bacterial species were Bacillus and Virgibacillus, followed by Lactobacillus and Trichococcus. Furthermore, the dominant fungi were found to be molds, such as Rasamsonia, Penicillium, Aspergillus, and Monascus, and the dominant yeasts were Saccharomyces cerevisiae, Saccharomycopsis fibuligera, Pichia anomala, and Debaryomyces hansenii. In general, the three types of Daqu showed slight differences in microbial communities, and the Shannon indexes (H') of the manually prepared and mechanically prepared Daqu were similar. The results suggest that mechanically prepared Daqu can replace manually prepared Daqu in liquor production, and this research provides useful information for liquor production and process improvement.

• Journal of Mushroom
• /
• v.18 no.3
• /
• pp.274-279
• /
• 2020

This study was conducted to investigate the characteristics of the medium used on the composting step, comparing the excavator agitator with the self-propelled turner. The temperature of the outdoor composting medium tended to increase rapidly after flipping in the turner. The late composting medium temperature was maintained at the excavator treatment area (farm practice), and the late composting effect progressed. During the field composting stage, various microorganisms such as Bacillus spp., Actinomycetes, fluorescent Pseudomonas spp., and filamentous fungi were distributed in the medium, and the density of aerobic bacteria involved in the decomposition of the medium was increased. Under high-temperature composting conditions, blue fungi, and mesophilic actinomycetes were inhibited or killed. Thermophilic actinomycetes, which play an important role in decomposing organic matter, showed higher densities than those observed in farm practices in the self-propelled turner process. The length of rice straw was slightly shorter when the self-propelled turner was used, and the water content did not show any significant difference between treatments. The a and b values tended to increase as the inverter was turned over. The CN ratio of the composting broth was lowered from 23.1 to 16.2 for the 5th turnover in the context of farming practices, and from 23.3 to 16.9 in the context of the self-propelled turner. The yield of each treatment was increased by 20% in 1 period, 28% in 2 periods, and 26% in 3 periods; the overall yield was 23%.

• Korean Journal of Soil Science and Fertilizer
• /
• v.37 no.3
• /
• pp.165-170
• /
• 2004

This study was conducted to investigate the effect of different surface soil management practices on soil microflora in volcanic ash soils of citrus orchard. Soil samples were collected from citrus orchards of clean cultivation, grass sod, and grass mulch system in May and September 1997. Soil chemical properties, populations of various microorganisms, enzyme activities, microbial biomass C were analyzed. Average soil pH were 4.7, and average nitrogen and organic matter contents were 6 and $140.2g\;kg^{-1}$, respectively. Aerobic bacteria were distributed at $26,2-47.3{\times}10^6cfu\;g^{-1}$ level. Among the aerobic bacteria Pseudomonas spp., Rhizobium spp., and thermophilic Bacillus spp. were dominant in most of the investigated orchard soils. Density of actinomycetes were low at $1.8-84.6{\times}10^5cfu\;g^{-1}$ level. Fungi were distributed at $26.4-182.1{\times}10^5cfu\;g^{-1}$ level and the density was higher in grass mulch and sward sites. In september, phosphomonoesterase activity was high at $239.6{\mu}g\;PNP\;g\;soil^{-1}\;h^{-1}$ in clean cultivated citrus orchards. Soil cellulase activity were higher at $602.6{\mu}g\;GE\;g\;soil^{-1}$\;24\;h^{-1}$ in grass sward cultivation than any other soil management practices. Soil microbial biomass C was higher in grass mulch cultivated orchards.

• Journal of Animal Science and Technology
• /
• v.46 no.2
• /
• pp.261-272
• /
• 2004

This study was conducted to investigate indices affecting composts maturity for swine manure compost produced in a commercial composting facility with air-forced from the bottom. The composting was made of swine manure mixed with puffing rice hull(6: 4) and turned by escalating agitator twice a day. Composting samples were collected periodically during a 45-d composting cycle at that system, showing that indices of Ammonium-N to Nitrate-N ratio were sensitive indicators of composting quality. Pile temperature maintained more than 62$^{\circ}C$ and water contents decreased about 20% for 25days of composting. A great variety and high numbers of aerobic thermophilic heterotropic microbes playing critical roles in stability of composts have been examined in the final composts, sbowing that they were detected $10^8$ to $10^{10}$ $CFUg^{-1}$ in mesophilic bacteria, $10^3$ - $10^4$ in fungi and $10^6$ - $10^8$ in actinomycetes, respectively. The results of this study for detennining a factor affecting compost stability evaluations based on composting steps were as follows; 1. Ammonium-N concentrations were highest at the beginning of composting, reaching approximately 421mg/kg. However Ammonium-N concentrations were lower during curing, reaching approximately l04mg/kg just after 45 day. The ratio between $NH_4-N$ and $NO_3-N$ was above II at the beginning of composting and less than 2 at the final step(45 day). 2. Seed germination Index was dependent upon the compost phytotoxicity and its nutrition. The phytotocity caused the GI to low during the period of active composting(till 25 days of composting time) depending on the value of the undiluted. After 25 days of composting time, the GI was dependent upon compost nutrition. The Gennination index of the final step was calculated at over 80 without regard to treatments. 3. E4: E6 ratio in humic acid of composts was correlatively decreased from 8.86 to 6.76 during the period of active composting. After 25 days of composting time, the E4: E6 was consistently decreased from 6.76 to 4.67($r^2$ of total composting period was 0.95). 4. Water soluble carbon had a tendency to increase from 0.54% to 0.78%during the period of active composting. After 25 days of composting time, it was consistently decreased from 0.78% to 0.42%. Water soluble nitrogen increased from 0.22% to 0.32% during the period of 15 days after initial composting while decreased from 0.32% to 0.21% after 15days of composting. In consequence, the correlation coefficient($r^2$) between water soluble carbon and water soluble nitrogen was 0.12 during the period of active composting mule was 0.50 after 25 days of composting time

• Korean Journal of Soil Science and Fertilizer
• /
• v.35 no.2
• /
• pp.127-135
• /
• 2002

This study was conducted to investigate the physico-chemical and microbiological properties in profile depth during composting process with different turning times when pig manure was composted with ground rice hulls at the rate of same for the promotion of the composting. The moisture contents, C/N rate and pH value decreased according to composting progresses as run into turning times, but increased those inside layer of the pile. $NH_4-N$ and $NO_3-N$ contents were high in the outer layer mostly, as the result the $NH_3$ flux was high in there, but it decreased as composting progresses. The number of aerobic bacteria were $10^7{\sim}10^9\;cfu\;g^{-1}$, increased as the turning times, the number of their showed high in the outer layer. The number of fungi were $10^2{\sim}10^4\;cfu\;g^{-1}$ at the early period of composting, but did't almost survive inside layer as composting progresses. The number of cellulose decomposer and thermophilic bacteria were $10^6{\sim}10^7\;cfu\;g^{-1}$ and $10^6{\sim}10^9\;cfu\;g^{-1}$, respectively, they showed high inside layer of the pile. Therefore, the turning of composting can reduce the change difference of microorganisms in the pile. Turning frequence for the promotion of composting showed approximately 2~3 times.

• Journal of Food Hygiene and Safety
• /
• v.4 no.2
• /
• pp.119-132
• /
• 1989

Gamma irradiation as a new physical treatment was applied to comparative investigates with a conventional ethylene oxide fumigant on the microbiological and physicochemical qualities of selected spices and dry vegetables such as powdered red pepper, black pepper, welsh onion, onion, garlic, carrot, korean cabbage and instant ramyon soup. The microorganisms contaminated in the sample, including total viable count, thermophilic bacteria, aerobic spore and fungi counts between the $10^4\;to\;10^6/g$ range. Coliforms were found only in black pepper and welsh onion powder as the $10^2\;to\;10^3/g$ level. A radiation dose of 7 to 10 KGy were sterilized completely to the contaminated microorganisms, while ehthylene oxide (E.O.) fumigation reduced of them to the $10^3/g$ level. An optimum dose of irradiation was less detrimental than E.O. fumigation to the physicochemical properties of the sample. Sensory evaluation after three months of storage at room temperatures showed that the overall acceptability of irradiated sample was higher than that of the non treated control as well as E.O. fumigated samples. Comparison gamma irradiation with E.O. gas treatment showed that E.O. treatment was less effective than radiation in cotrolling microbial contamination of spices and vegetables.