• Korean Journal of Microbiology
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• v.30 no.6
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• pp.444-449
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• 1992

A total of 858 heterotrohic bacteria were isolated and analyzed hy numerical method to investigate the heterotrophic hacterial community structure in Naktong Estuary. Although the values of H' (Shannon's diversity index). ranged between 1.54 and 3.49. were similar with those of the data hefore the construction of Naktong River barrage, however J' (evenness index. 0.31-0.80) was reduced. Physiological tolerance index for water temperature ($P_{s}$) was high at St.l and 2 whose depthes arc shallower than the other stations. and indices for pH ($P_{h}$) and salinity ($P_{s}$) were high at St. 2. 3. 4 where freshwater and seawater arc mixed. The predominant clusters were identified as Aeromonas. Vihrio. Pseudomonas. Acinelobacter-Morexella. Alcaligenes. Flavobacterium. Micrococcaccae. and Enterohacteriaceae. The kinds nf the isolates were similar with the previous result. hut the dominant genus was changed. These results suggest that the environmental changes in Naktong Estuary affect the hacterial physiological adaptation rather than the composition of heterotrophic hactcrial community.

• Journal of Microbiology
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• v.39 no.3
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• pp.240-243
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• 2001

The effect of cryoprotectants and suspending solutions on the preservation of marine heterotophic bacteria was investigated. Six halotolerant and four halophilic bacterial isolates suspended in either distilled water or artificial seawater were preserved in glycerol and dimethylsulfoxide at -70$\^{C}$, respectively. After one year of preservation, the recovery rates on the appropriate agar plates were estimated. The survival rate was found to be dependent on the strain tested, regardless of the preservation conditions tested.

• Korean Journal of Microbiology
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• v.28 no.4
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• pp.324-330
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• 1990

The distribution of physicochemical environmental factors and microbiological factors was studied at 6 sampling sites in Kyeongge Bay of Yellow Sea from October 1989 to October 1990. The total bacterial number, saprophytic bacterial number, petroleum-degrading bacterial number, bacterial biomass, and bacterial secondary production were measured in the range of 0.09~1.24*10$^{7}$ cells/ml, 7~60000 CFUs/ml, 0~240 cells/ml, 14.16~301 .$\mu$g-C/l, and 0.13~11.82 mg-C/m$^{3}$/hr, respectively. The turnover times of $^{3}$H-glucose and $^{3}$H-acetate were in range of 6.5~6984 and 41~24897 hours, respectively. The spatial distribution of heterotrophic bacterial communities were hightly affected by influx of organic pollutants from the coastal area and the seawater exchange with offshore.

• Journal of Environmental Health Sciences
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• v.32 no.4 s.91
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• pp.353-358
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• 2006

This study was performed to evaluate the effects of input ratios of bulking material in aerobic composting of food wastes on variation of colony forming units of heterotrophic bacteria. Wood chips were used as a bulking material. Volume ratios of food wastes to wood chips in reactor of Control, WC-1 and WC-2 were 10/0, 10/5 and 10/10, respectively. Reactors were operated for 24 days with 1hour stirring by 1rpm and 2 hours of the forced aeration per day. WC-2 reached high temperature range faster than WC-1, and the maximum temperature of WC-2 was higher than that of WC-1. This means that the reaction velocity of composting of WC-2 was faster than that of WC-1. Judging from the profile of pH changes, composting of WC-1 proceeded slowly and continuously. Composting of WC-2 proceeded rapidly in the former half reaction period, and kept steady state of high pH in the latter half reaction period. Namely, composting of WC-2 was nearly completed in the former half reaction period. In the case of WC-1 and WC-2. the maximum temperature was followed by the rapid pH increase in 2-3 days, and this was followed by the maximum Colony Forming Units(CFU) in 3 days. But, these three items of WC-2 always appeared faster and higher than those of WC-1.

• Journal of fish pathology
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• v.13 no.1
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• pp.67-73
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• 2000

This study was carried out to elucidate the preliminary ecosystem of the heterotrophic bacterial flora in Kunsan Bay located in western costal area of Korea. Samples were collected at 5 sampling stations. Among 123 bacterial isolates, 9 genera of bacteria were appeared as follows; Vibrio spp.(44 isolates/35.7%), Pseudomonas spp.(42 isolates/34.1%), Aeromonas spp.(11 isolates/8.9%), Moraxella spp.(9 isolates/7.3%), Enterobacteria spp.(6 isolates/4.8%), Bordetella spp.(3 isolates/2.4%), Alkaligenesis spp.(3 isolates/2.4%), Flavobacterium spp.(2 isolates/1.6%), and Staphylococcus spp.(3 isolates/2.4%) respectively. Total viable heterotrophic bacteria was ranged from $5{\times}10^3$ to $1{\times}10^5$ CFU/ml and the most abundant viable counts of bacterial population were showed at the stations 2 and 3. This result indicates that the coastal area around Kunsan bay is getting to contaminate far more by municipal wastewaters and industrial byproducts. and so the outbreak of the bacterial diseases will be increased in fish farms.

• Environmental Engineering Research
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• v.22 no.1
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• pp.55-60
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• 2017

Provision of safe, accessible, and good water quality in the community is an important step towards reducing various waterborne illnesses. However, improving the quality of water should include spreading awareness to the public regarding the importance of cleaning their household water tanks. The aim of this study was to investigate the microbial quality of water of household water tanks in Dubai. The water samples from household water tanks were collected from forty houses, and a questionnaire was given to the residents to determine the history of the water tanks. The membrane filtration technique was used to quantify heterotrophic and total coliform bacteria on plate count agar and the violet red bile agar respectively. The overall results of this study have shown that 18 out of total 40 household water tanks contained different types of bacteria concentration level beyond local and widely accepted international standards. The overall results of this study indicated that there is a lack of awareness among residents regarding the importance of maintaining proper sanitation and hygiene of the household water tanks.

• Journal of the Korean Society for Marine Environment & Energy
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• v.3 no.4
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• pp.65-75
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• 2000

The roles of environmental factors affecting on heterotrophic bacterial distribution at Hangam Bay and Masan Bay in which occurred frequently red tide, during June to November 1996 were investigated. The aquatic environment of Masan Bay and Haengam Bay showed difference in the contents of inorganic nutrients. Haengam Bay may be defined as nitrogen limited aquatic environment. On the other hand, Masan Bay appeared to the appropriate N/P molar ratio of mean 15.9 during the periods of study. By the results of simple regression, chlorophyll a showed significant correlation with precipitation (r=0.813, P<0.05) and phosphorus (r=0.846, P<0.05) at Haengam Bay, but not showed significant correlation with parameters at Masan Bay. The heterotrophic bacteria showed significant correlation with many environmental parameters at Masan Bay (Precipitation, r=0.990, P<0.01 : NO₃-N, r=0.901, P<0.05 : Dissolved inorganic nitrogen, r=0.899, P<0.05 ; N/P molar ratio, r=0.952, P<0.05 : Salinity, r: -0.934, P<0.05) than Haengam Bay (SiO₃-Si, r=0.960, P<0.01). By the results of multiple regression, the chlorophyll a was varied with only 2 factors in Masan Bay (R²=0.100) and 3 factor in Haengam Bay (R²=0.903). The major factor which affected to chlorophyll a was SiO₃-Si (R²%=67.8) in Masan Bay, and -N/P (R²%=37.6) in Haengam Bay. The heterotrophic bacteria were varied with 4 factors in Masan Bay (R²=100) and 2 factor in Haengam Bay (R²%=0.878). The major factor, which affected to heterotrophic bacteria, was SiO₃-Si (R²%=42.3) and salinity (R²%=32.1) in Masan Bay, and SiO₃-Si (R²%=76.3) in Haengam Bay. Resultingly, the influx of freshwater in Masan and Haengam Bay was enriched in inorganic nutrients, and plays an important role in the change of heteroterophic bacteria and chlorophyll a during early summer to autumn.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.25 no.4
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• pp.307-313
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• 1992

To study the seasonal variation of heterotrophic bacteria near the surrounding seawater of Porphyra forming area, samples were collected in the intertidal waters of Mokp'o of the Yellow Sea from February to December, 1990. Annual distribution of heterotrophic bacteria ranged from $7.5\times10^2\;to\;1.1\times10^5\;cfu/ml,$ annual distribution of physiological characteristic bacteria ranged from $5.0\times10\;to\;4.34\times10^4\;cfu/ml$ for proteolytic bacteria, from 0 to $1.35\times10^4\;cfu/ml$ for lipolytic bacteria and from 0 to $1.2\times10^4\;cfu/ml$ for amylolytic bacteria. Sixty-five percent of isolates from seawater were rods, and $76.7\%$ of isolates were Gram-negative. Most isolates were mesophiles and showed utilization of various carbon sources such as glucose, maltose, lactose, sucrose and arabinose. Most isolates also showed tolerance to a broad range of salt concentration. Dominant genus in seawater were Flavobacterium spp., in February, Moraxella spp., Acinetobacter spp. in March, Bacillus spp., Chromobacterium spp., Micrococcus spp., Vibrio spp. in July and Chromobacterium spp., Micrococcus spp., Bacillus spp. in November.

• Journal of Korea Soil Environment Society
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• v.1 no.2
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• pp.35-42
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• 1996

Seawater samples were collected from P'ohang coastal area during April 1995 - January 1996. The distribution of total heterotrophic bacteria and crude oil-degrading bacteria (CDB) were studied. In addition, biodegradation of crude oil was investigated through mono and mixed culture. The heterotrophic bacterial distribution was in the range of 4.1 $\times$ $10^4$- 1.2 $\times$ $10^5$ CFU/$m\ell$, respectively. The percent of crude oil-degrading bacteria against total heterotrophic bacteria was 0.05-0.54% which was lower than other marine samples reported. Therefore it could be suggested that the distribution of crude oil-degrading bacteria in the seawater of P'ohang coastal area was highly affected by presence of petroleum hydrocarbon. Taxonomical characteristics of 26 isolates were investigated. The results of identification were showed 7 genera which were Acinetobacter spp., Bacillus spp., Citrobacter spp., Micrococcus spp., Moraxella spp., Rhodococcus spp., and Serratia spp. Appearance of Enterobacteriaceae indicated that the seawater was polluted with wastewater. Also genus of Bacillus had predominant in CDB on P'ohang coastal area. In flask culture, biodegradation of crude oil was enhanced by addition of mixed culture of CDB.

• Korean Journal of Soil Science and Fertilizer
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• v.20 no.2
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• pp.193-197
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• 1987

Associative heterotrophic nitrogen fixing bacteria were identified by immunodiffusion method in the histosphere of Planta-ginaceae, Caryophllaceae, Gramineae, and two types of rice cultivars. Twenty four strains associative heterotrophic bacteria with high ARA (more than 10nmole/tube/hr) were isolated from the histosphere of grasses and rice.* Those strains were related with 8 species of Azospirillum, 11 species of Pseudomonas, 2 species of Klebsiella and 2 species of Agrobacterium. Among them Azospirillum sp. and Pseudomonas sp. were predominant in histosphere of grasses and rice cultivars. From the histosphere of Oryza sativa, and Sagina maxima, the strains of Azospirillum, Pseudomonas, Klebsiella, and Agrobacter were identified while Pseudomonas was identified from Ischaemum anthephoroides, Plantago lanceolata, Miscanthus sacchuriflorum, and only Azospirillum was identified from Zoisia sinica, respectively. Associative nitrogen fixing heterotrophic bacteria were more abundant in the histosphere of Oryza sativa and Sagina maxima than that of other grasses grown in saline and reclaimed saline paddy soil.