Numbers Of Aerobic Heterotrophic Bacteria Research Articles

Microbiological quality of well water from Koprivnica-Križevci County in 2018

In this study, microbiological quality of drinking water deriving from the private wells from Koprivnica-Križevci County was investigated. A total of 287 samples from different locations were collected during 2018 and analysed for the following microbiological parameters: total coliforms, Escherichia coli, Enterococcus spp., Clostridium perfringens, Pseudomonas aeruginosa, and the number of aerobic heterotrophic bacteria at 36 °C and 22 °C. The results showed that 24 % of the analysed water samples were of unsatisfactory microbiological quality, with high incidence of faecal contamination. Well water is still the main source of drinking water for many residents of this County, especially in its rural parts, so continuous monitoring and disinfection of drinking water deriving from private wells is of exceptional importance for the public health.

Effect of Liquid Organic Fertilizers and Soil Moisture Status on Some Biological and Physical Properties of Soil

<p>This study was conducted to evaluate the effects of liquid organic fertilizers (LOFs) and soil moisture status on some biological and physical properties of postharvest soil of maize cultivation. For this purpose, a factorial greenhouse experiment was performed based on the completely randomized design with three replications. Treatments consisted of five levels of LOFs (control, vermicompost tea, vermiwash, plant growth-promoting rhizobacteria [PGPR] enriched vermicompost tea and PGPR enriched vermiwash) and three levels of soil moisture status (field capacity [FC], 0.8 FC and 0.6 FC). The results showed LOFs caused an increase of soil biological properties (soil microbial respiration, soil microbial biomass, dehydrogenase activity and the number of aerobic heterotrophic bacteria) and the improvement of soil physical condition. LOFs increased aggregate stability, hydrophobicity and total porosity, while decreased bulk density and soil penetration resistance. Increasing water stress levels reduced soil biological activity and made soil physical properties more unfavorable. In general, LOFs improved soil conditions by enhancing soil physical and biological properties and decreased the negative effects of water stress. In addition, results showed that LOFs enriched with PGPR could be more effective than non-enriched ones.</p>

Investigation of the effects of various stress factors on biofilms and planktonic bacteria in cooling tower model system.

Biofilm is a microbial population which live in a self-produced extracellular polymeric matrix by attaching to surfaces. Biofilms consist of different different types of organisms such as bacteria, fungi, protozoa, etc. Many biofilms that develop in nature consist of more than one type of organism. Biofilms protect bacteria from adverse conditions such as temperature fluctuation and disinfectants. The aim of this study was to determine the effective elimination strategies for combating biofilm and planktonic bacteria in cooling tower model system using different decontamination / disinfection techniques. In this study, 14week-old biofilms were treated with temperatures of 4°C, 65°C; pH of 3, 11; 2 and 10mg/l chlorine, 2 and 10mg/l monochloramine; hypotonic salt (0.01% NaCl) and hypertonic salt (3% NaCl) solution. For enumeration, number of aerobic heterotrophic bacteria was determined by conventional culture method, number of live bacteria was determined by LIVE/DEAD viability kit, CTC-DAPI and Alamar blue staining methods. Temperature of 65°C, pH of 3, 10mg/l monochloramine and hypertonic salt solution were the most effective parameters for decontamination of biofilm and planktonic bacteria. Biofilm bacteria in the circulating water system were significantly more resistant than planktonic bacteria against stress factors. When the numbers of epifluorescence microscopy and conventional culture technique were compared, significantly higher number of live bacteria were detected using epifluorescence microscopy. Bacteria enter the viable but non-culturable phase by loosing their culturability under stress conditions. For this reason, the conventional culture method should be supported by different techniques to get more realistic numbers.

Diversity of bacterial forms in ice wedge of the Mamontova Gora glacial complex (Central Yakutiya)

Electron microscopic investigation of four samples of ancient ice wedge from the Pleistocene glacial complex of Mamontova Gora (Yakutiya, Russia) revealed high diversity of bacteriomorphic particles. Their structural features included the presence of electron-transparent zones, presumably inclusions containing storage compounds, and microenvironment (capsules or external sheaths). These features may be a result of adaptive strategies providing for microbial survival under permafrost conditions. Predominance of rod-shaped forms morphologically resembling coryneform actinobacteria was found. X-ray microanalysis revealed organic origin of bacteriomorphic particles. Some particles were characterized by incomplete spectra of the major biogenic elements, resulting probably from low-temperature damage to the cellular structures. Total numbers of aerobic heterotrophic bacteria determined by plating on nutrient media were comparable to the values obtained for permafrost soils and Arctic ice. Predominance of coryneform actinobacteria was observed. Abundance of these evolutionarily early groups of actinobacteria may indicate the ancient origin of the microflora of the relic frozen rocks.

Soil Microbial Community Diversity and Its Relationships with Geochemical Elements under different Farmlands in Shouguang, China

The aims of this study were to investigate soil microbial community characteristics and their interrelationships with soil geochemistry under different farmlands in Shouguang, China. The traditional dilution plate counts, BIOLOG system, and fatty acid methyl ester (FAME) analyses were used to assess microbial populations, substrate utilization, and fatty acid profiles. The number of aerobic heterotrophic bacteria varied significantly among untilled land, maize, and mungbean fields. The amounts of actinomycetes, fungal fatty acids, and Gram-positive/Gram-negative bacteria ratios varied greatly among celery, tomato, and aubergine fields. In the tomato field, the soil microbial community characteristics were significantly different from other fields. Principal component analysis of BIOLOG and FAME data revealed differences in the catabolic capability and fatty acid profiles of soil microbial communities among different farmlands. Spearman correlation analyses showed that in these sand clay soils of Shouguang, microbial communities in different farmlands were closely correlated with soil geochemical elements, moisture, and organic matter.

Predicting Stability of Distiller’s Wet Grains (DWG) with Color Analysis

Distiller’s wet grain (DWG) is one of the coproducts from the fuel ethanol industry. Although many studies have investigated the nutritional properties of DWG, little work has investigated the storability and shelf life for these feed products or how to measure these quantities. The objectives of this research were to measure the development of microorganisms and their respiration over time in freshly produced DWG and to determine if there was a quantitative relationship between these microbiological parameters and a more easily measured physical property, DWG color. The numbers of aerobic heterotrophic bacteria, molds and yeasts, and carbon dioxide generated by microbial respiration were measured at t = 0, 1, 2, 4, and 7 days as were Hunter color (L, a, b) values. All of the microbial parameters increased significantly over time (p < 0.05). Hunter L and a values appeared to change over time as well, but these differences became significant only at t = 7 days; at this time period, Hunter b changed significantly also. Hunter a and b values were negatively correlated with aerobic heterotroph numbers (r = −0.74 for Hunter a; r = −0.77 for Hunter b), yeast and mold counts (r = −0.78 for Hunter a; r = −0.81 for Hunter b), and CO2 production (r = −0.89 for Hunter a; r = −0.87 for Hunter b). Hunter L values had moderate positive correlations with the microbial parameters (r values ranged from 0.42 to 0.57). Using Hunter a and b color parameters as predictor variables, multiple linear and nonlinear regressions produced R2 values of 0.751, 0.665, and 0.816 for aerobic heterotrophs, molds and yeasts, and CO2 generation, respectively. Additional research should quantify spoilage criteria, the relationship to palatability, and determine how best to use color changes as indicators of each.

A short Communication: Distribution of heterotrophic bacteria in the sediments in the mangrove swamp at Gazi Bay, Kenya

In the first ever study of microorganisms in an East African mangrove swamp, the number of aerobic heterotrophic bacteria in the mangrove swamp sediment was investigated and found to range from 7.44 × 106 to 4.70 × 108 cfu/g dry wt, (cfu = colony forming units; g dry wt = gram dry weight). The anaerobic heterotrophic bacteria ranged from 7.45 × 106 to 1.82 × 108 cfu/g dry wt. There was no significant difference between the Avicennia marina, Ceriops tagal and Rhizophora mucronata sediments with respect to the number of aerobic and anaerobic bacteria. The exercise was conducted between October and February and generally lower numbers of bacteria were recorded between mid December and February. Key words: Mangrove swamps, heterotrophic bacteria Journal of Tropical Microbiology Vol.1(1) 2002: 41-46

Effect of Hydrologic and Geochemical Conditions on Oxygen-Enhanced Bioremediation in a Gasoline-Contaminated Aquifer

Oxygen addition to enhance bioremediation of gasoline-contaminated ground water was performed in two locations of a shallow aquifer in South Carolina characterized by benzene, toluene, and methyl tert-butyl ether (MTBE) at concentrations greater than 1 mg/L, respectively. Oxygen addition with an oxygen-release compound (a proprietary form of magnesium peroxide [MgO2]) produced markedly different results with respect to dissolved oxygen (DO) generation and contaminant decrease in the two locations. Oxygen-release compound injected at the former underground storage tank (UST) source area did not significantly change measured concentrations of DO, benzene, toluene, or MTBE. Conversely, oxygen-release compound injected 200 m downgradient of the former UST source area rapidly increased DO levels, and benzene, toluene, and MTBE concentrations decreased substantially. The different results can be related to differences in hydrologic and geochemical conditions that characterized the two locations prior to oxygen addition. For example, the contaminated aquifer downgradient of the former UST source area was anoxic, but frequently received oxygen-saturated recharge during rainfall events. As such, the aquifer was characterized by low concentrations of reduced species (such as ferrous iron (Fe2+), as well as relatively high numbers of aerobic heterotrophic bacteria (as most probable number [MPN] per milliliter). In contrast, recharge does not occur in the paved, former UST source area. The anoxic aquifer was characterized by higher concentrations of Fe2+ that exerted a significant chemical oxygen demand on the oxygen injected, and much lower numbers of aerobic heterotrophic bacteria. The results of this investigation indicate the important role that pre-existing hydrologic, geochemical, and microbiologic conditions have on the outcome of oxygen-based remediation strategies, and suggest that these properties should be evaluated prior to the implementation of oxygen-based remedial strategies.

Reduction of nitrate in clayey subsoils controlled by geochemical and microbial barriers

Vertical distribution of redox zones, concentrations of redox‐sensitive constituents, numbers of aerobic heterotrophic bacteria, and potential denitrification activity were studied in 1‐m cores taken at the transition between the oxidized and reduced layers in two Danish clayey subsoils. Based on the matrix soil colors, a redox sequence of oxidized, suboxic, and reduced zones was identified at both sites. The geochemical composition of the oxidized brown colored zone (to depths of 2.6 and 3.2 m) was characterized by high concentrations of NO3 − and low amounts of total organic carbon, exchangeable forms of NH4 +, Fe2+, and Mn2+, and structural Fe(II) in the clay minerals. In the underlying 20‐ to 30‐cm‐deep suboxic zone, decreasing NO3 − concentrations were observed together with increasing amount of exchangeable forms of Fe2+ and Mn2+, and structural Fe(II). Finally, in the reduced grey zone, NO3 − was no longer present and maximum concentrations of other redox sensitive constituents occurred. Throughout the subsoils, the distribution of exchangeable Fe2+ corresponded most closely to changes in the colors of redox zones. The low‐organic Havrebjerg site displayed geochemical profiles indicating that NO3 − was chemically reduced by structural Fe(II) in the clay minerals of the suboxic zone, and that the Fe(II) formed a geochemical barrier for the downward progression of NO3 −. Aerobic heterotrophic bacteria occurred only in low numbers at this site and potential denitrification activity was very low. In contrast, the Sparresholm site had a significant population of bacteria in the suboxic zone, which also contained a heterogeneous distribution of potential denitrification activity. Specific microsites with facilitated transport of soluble organic substrates are proposed to support the denitrification activity in a heterogeneous distribution, constituting a microbial barrier for downward progression of NO3 − in this subsoil.

Microbial degradation of petroleum hydrocarbons in estuarine sediment of Tama River in Tokyo urban aera

Aerobic and anaerobic biodegradation rates of petroleum hydrocarbons, i.e., hexadecane (HEX), phenanthrene (PHE), and anthracene (ANT), were determined in estuarine sediment of the Tama River in urban Tokyo, followed by estimating their respective degradation potential. While in a sediment slurry, the aerobic biodegradation rates of these petroleum hydrocarbons ranged from 40 to 70 μg·g−1 dry sediment· day−1. The anaerobic biodegradation rate of HEX was found to be 5 - 8 μg·g−1 dry sediment· day−1, whereas that of PHE and ANT could not be detected following a 2-month incubation. Aerobic degradation of HEX was not affected by coexistence with either PHE or ANT, nor by the salinity level. The number of HEX-, PHE-, or ANT-utilizing bacteria ranged from 5 - 10% of the total number of aerobic heterotrophic bacteria. We calculated their biodegradation potentials using the biomass of naturally existing petroleum hydrocarbon-utilizing bacteria present in the sampled sediment, with results for HEX, PHE, and ANT being 1.0 − 3.5, 4.2 × 10−2, and 1.2 × 10−2 − 9.4 × 10−1 μg·g−1 dry sediment· day−1, respectively. In the aerobic tidal sediment of the Tama River, the purification potentials of HEX, PHE, and ANT were assessed to be approximately equal to their accumulation potentials occurring at the normal water level.

Microbial degradation of petroleum hydrocarbons in estuarine sediment of tama river in Tokyo urban aera

Aerobic and anaerobic biodegradation rates of petroleum hydrocarbons, i. e., hexadecane (HEX), phenanthrene (PHE), and anthracene (ANT), were determined in estuarine sediment of the Tam River in urban Tokyo, followed by estimating their respective degradation potential. While in a sediment slurry, the aerobic biodegradation rates of these petroleum hydrocarbons ranged from 40 to 70 μ g·g-1 dry sediment-1 day. The anaerobic biodegradation rate of HEX was found to be 5 - 8 μ g·g-1 dry sediment day -1, whereas that of PHE and ANT could not be detected following a 2-month incubation. Aerobic degradation of HEX was not affected by coexistence with either PHE or ANT, nor by the salinity level. The number of HEX-, PHE-, or ANT-utilizing bacteria ranged from 5 - 10% of the total number of aerobic heterotrophic bacteria. We calculated their biodegradation potentials using the biomass of naturally existing petroleum hydrocarbonutilizing bacteria present in the sampled sediment, with results for HEX, PHE, and ANT being 1.0 - 3.5, 4.2 x 10-2, and 1.2 x 10-2- 9.4 x 10-1 μ g·g-1 dry sediment day-1, respectively. In the aerobic tidal sediment of the Tama River, the purification potentials of HEX, PHE, and ANT were assessed to be approximately equal to their accumulation potentials occurring at the normal water level.

Biological properties of soil and subsurface sediments under abandoned pasture and cropland

Little is known about the effects of most surface land-use practices on shallow subsurface microbial communities. We analyzed duplicate cores taken aseptically from up to 10 m depth from unconsolidated valley sediments (soils) beneath an abandoned pasture reverting to tall grass prairie and cropland. Both profiles had similar soil texture, with moderately higher silt under cropland and a slight decrease in clay with depth. Soluble organic C was about two times higher in the grassland site and dissolved O 2 was about 8% lower compared with the cropland site. Water content and C-to-N ratios were greatest at the grassland surface but were less in the grassland than the cropland site within 2 m depth. In general, numbers of aerobic heterotrophic bacteria and protozoa decreased with depth until the saturated zone (4.3 m in grassland and 5.3 m in the cropland site). Bacterial numbers as determined by plate counts were about 10-fold less at the groundwater interface than in the surface soils at both sites. Direct microscopic counts of total bacteria were approximately the same in the surface soil and the sediments at the top of the water table at both sites. The top of the water table generally did not exhibit elevated microbial biomass or activity relative to deeper sediments. There was no significant relationship between protozoan numbers and microbial thymidine uptake at the cropland site, but a negative relationship was observed at the grassland site. The data suggest that cultivation may affect microbial biomass and activity in the subsurface, as well as community interactions between protozoa and bacteria.

Effects of Heating on the Microbial Populations of a Grassland Soil

Effects of burning on soil bacteria were studied under laboratory conditions on grassland soil samples. Low intensity fire conditions were simulated in a muffle furnace (temperature of 450°C for 3 min). The number of aerobic heterotrophic bacteria and sporeformers was studied in heated and unheated samples. Immediately after burning, the number of bacteria decreased; an increase resulted however after 24 hours and after 10 days. Thirty days after treatment the number of bacteria decreased again in the treated samples, achieving values similar to the unburned soil. The laboratory procedure presented in the paper seems to be a useful approach to simulate field conditions where fire experiments are difficult to manage.

Factors relating to the abundance of bacteria in the mangrove estuary of Nakama River, Iriomote Island, Okinawa.

Physical, chemical and bacteriological examinations of water and mud from the mangrove estuary of Nakama River were carried out. The numbers of total bacteria in the water were one order of magnitude larger in summer than in winter, on the average, and had close correlations with a lot of variables such as, chlorinity, concentrations of nitrate, nitrite, ammonia, total nitrogen, particulate carbohydrates, particulate amino acids and chlorophyll α in the water. The numbers of aerobic heterotrophic bacteria in the mud showed the same seasonal pattern as that for water bacteria, and had strong correlations with the concentrations of inorganic phosphate, ammonia and total nitrogen in the pore water as well as the contents of total carbohydrates and total amino acids in the mud. Interactions among water-related and mud-related variables were not so evident with few exceptions. The models for predicting bacterial abundance in the ecosystem are proposed by multivariate analysis, and the influence of environmental variables on the temporal and spatial distributions of bacteria in the estuary is discussed.

Seasonal distribution of facultatively enteropathogenic vibrios (Vibrio cholerae, Vibrio mimicus, Vibrio parahaemolyticus) in the freshwater of the Elbe River at Hamburg.

Between June 1981 and December 1982 the incidence of Vibrio cholerae, V. mimicus and V. parahaemolyticus was determined at two sampling sites on the Elbe River at Hamburg. A total of 183 strains was isolated from 147 water samples. Of these, 107 belonged to non-01 V. cholerae (ten strains producing a cholera-like enterotoxin); 33 were identified as V. mimicus, including two enterotoxin producers; 42 strains were Kanagawa-negative cultures of V. parahaemolyticus; and one was V. fluvialis. The highest incidence was observed from June to September with about 10(2) organisms/l. Halophilic vibrios, less than five organisms/l, were detectable during the period June/July to October. The vibrio incidence was not influenced by the numbers of aerobic heterotrophic bacteria, coliforms or faecal bacteria. In general water temperature correlated with the seasonal variation. Thus, a temperature rise over 10 degrees to 20 degrees C was followed by a distinct increase in vibrio numbers. Of 14 chemical parameters only chloride concentration might have had an influence on the seasonal variation. It is concluded that the three Vibrio species are indigenous organisms of the Elbe River.

多摩川上流域における好気性従属栄養細菌数の季節変動とそれの環境要因との関係について

Seasonal fluctuations were studied for water temperature, pH, dissolved oxygen, BOD, COD, NO3-N, discharge, amount of chlorophyll a (Chl. a) +phaeophytin a (Phae. a) and the number of aerobic heterotrophic bacteria in water, and dry weight, amount of Chl. a+Phae. a and the number of bacteria in periphyton in the upstream area of the Tamagawa River in Tokyo, Japan. The number of bacteria in water fluctuated between 3.0 103 and 1.4 104 cells cm-3. Generally, they are numerous when the discharge was small and vice versa. During the flood stage, in spite of huge flow, the number of bacteria was large. The periphyton of the river bed exfoliated when the discharge was large, and the amount of Chl. a+Phae. a did not increase over 100 mg Em-2. The number of bacteria in periphyton and the amount of Chi. a+Phae. a have a high correlation coefficient (r=0.868). The percentage of pigment producing bacteria rose with the increase of Chl. a+Phae. a, suggesting a bacterial community relating to the epiphytic algae. After exfoliation of periphyton, the number of bacteria did not decrease as much as the amount of Chl. a+Phae. a, suggesting another bacterial community not depending on them. No correlation between the number of bacteria in water and that in periphyton was observed.

Soil and Rhizosphere Microorganisms in Amended Coal Mine Spoils

AbstractTopsoil is usually respread over strip‐mined land during reclamation. In some instances, spoil could be used as a medium for revegetation. The objectives of this study were to compare microbial parameters in spoil and soil and determine the effect of spoil amendment on these microbial parameters.Representative samples from a topsoil stockpile, a nonvegetated spoil, a reclaimed area, and an adjacent undisturbed surface soil were collected from the San Juan coal mine near Farmington, N. Mex. Additional samples of spoil and stockpiled topsoil were used in a greenhouse pot experiment to determine the influence of spoil amendment on microbial parameters. The treatments included spoil, spoil plus topsoil inoculant, spoil plus alfalfa hay and fertilizer (both with and without topsoil inoculant), and spoil plus gamma‐irradiated sewage sludge (both with and without topsoil inoculant). The pots were planted to Bouteloua gracilis and microbial determinations of the spoil made after 5 months. Later the same pots were replanted to Atriplex canescens and microbial determinations made of the rhizosphere 7 months after planting. Microbial parameters measured included numbers of aerobic heterotrophic bacteria, Streptomyces, fungi, ammonium oxidizers, and aerobic asymbiotic nitrogen fixers, dehydrogenase activity, and fungal genera distribution.The undisturbed soil and reclaimed area had comparable microbial numbers, dehydrogenase activity, and fungal genera distribution. Microbial numbers and dehydrogenase activity of stockpiled topsoil and nonvegetated spoil were low and the fungal genera distribution was narrow.Topsoil inoculation did not increase microbial parameters of the spoil or of the rhizosphere of A. canescens. Spoils appeared to be unable to support an active and varied indigenous flora or the microorganisms introduced by the topsoil inoculant. Organic amendment of either sludge or alfalfa increased all microbial parameters. The increased numbers, dehydrogenase activity, and distribution of fungi were particularly evident in the rhizosphere. Providing an available carbon source was more critical in stimulating an active and varied spoil microflora than was supplying an inoculant source.

相模川の好気性従属栄養細菌フローラ

The number and flora of aerobic heterotropic bacteria were studied for running water, Aufwuchs and river bed sediments of the Sagami River, Kanagawa Prefecture. The numbers of aerobic heterotrophic bacteria were 104-106 cells/ml in water and 106-107 cells/cm2 in Aufwuchs. In the river water, Flavobacterium was the most predominant bacterial genus which accounted for 31.3-43.8% of the total heterotrophic bacteria, and Acinetobacter and Moraxella were followed as the secondarily predominant bacteria. These three genera comprised 50-75% of the total heterotrophic bacteria. More Flavobacterium was found in periphyton than in water.

富栄養河川における付着微生物群集の発達にともなう現存量および光合成量の変化

Microbial succession and changes in photosynthetic rate attendant on the film development of periphyton were investigated using artificial substrata in a shallow eutrophic region of the midstream of the Tamagawa River. Bacteria played the role of pioneer colonizer in the periphyton development. Algae joined the community after formation of bacterial colonies on substrata and dominated in the mature stage. Algae accounted for about 80 percent of the periphyton community in maximum and 50-70 percent in carbon weight under ordinary conditions in spring. Total numbers of aerobic heterotrophic bacteria were 107-109 cells/cm2 and 1010-1012 cells/gC in the mature stage. A number of sulfate-reducing bacteria were also found in that stage. Photosynthetic rates of sessile algae varied widely with film development of periphyton. They showed 3-20mg·O2/mg·chl.-a·hr in the early stage and 1-3mg·O2/mg·chl.-a·hr in the mature stage. An extremely low photosynthetic rate was found just before the exfoliation of periphyton occurred.

FACTORS INFLUENCING VIABLE BACTERIA IN A TURBID MAN-MADE IMPOUNDMENT

SUMMARY The numbers of aerobic heterotrophic bacteria in the waters and sediments of the small turbid impoundment, Wuras Dam, are very high (≥100 000 ml −1 and ≥ 1x106 bacteria g−1 respectively). Viable bacterial numbers in the open water seem to depend on suspen-soid concentrations and the regression line: is proposed to describe this relationship. Allochthonous inputs of suspensoids and resuspension of surface sediment layers seem to influence suspensoid concentrations of the open water and hence the bacterial numbers. In the littoral zone dense stands of Phragmites australis and Typha latifolia sub-species capensis seem to increase the numbers of viable bacteria of the surface water. There were significantly (p = 0,05) higher numbers here compared to the surface of the open water. The microbiology of the waters and sediments of this turbid impoundment appears to differ greatly from that of clear water lakes.