Total Heterotrophic Bacterial Population Research Articles

Bioremediation of a crude oil contaminated soil using water lettuce (<i>Pistia stratiotes</i>)

Laboratory-scale studies were carried out using a nutrient formula produced from Pistia stratiotes plant to achieve bioremediation of crude oil impacted loamy soil. This study assessed the efficacy of powdered Pistia stratiotes as potential bio stimulant in the remediation of crude oil contaminated soil using three test treatments (20ml, 60ml and 100ml) at three test concentrations (20g, 40g and 60g) of nutrient and a control (0g). The remediation process was monitored by assaying the total hydrocarbon content (THC) and soil pH before and after amendment with the powdered P. stratiotes for 90 days. The result showed increase in soil pH and THC in comparison with the control due to soil contamination by crude oil. However, there was a significant reduction (p < 0.05) in soil pH and THC with the introduction of powdered P. stratiotes at different concentrations. Contaminated soil amended with 40g of P. stratiotes had the highest THC loss of (30%) on the final day of remediation. In a 90 day study, the control set-up had its total culturable heterotrophic bacterial population of the P. stratiotes recipe increase from 1.4×107 Cfu/g to 2.8×107 Cfu/g, while the total culturable heterotrophic fungal count in the P. stratiotes treatment ranged from 7.0×104 Cfu/g to 4.0×104 Cfu/g. Statistical analyses showed significant difference at p ≤ 0.05 level for the two conditions (Pistia stratiotes nutrient treated soil and control). The total culturable hydrocarbon utilizing bacteria in P. stratiotes treated polluted soil increased from 1.0×106 Cfu/g to 6.8×105 Cfu/g, while the total culturable hydrocarbon utilising fungal counts increased significantly from 1.9×104 Cfu/g to 4.8×104 Cfu/g for P. stratiotes treatment. The results from this research demonstrated that powdered P. stratiotes is an effective agent that can be used to decrease the pH of contaminated soil and improve soil properties, hence aids in remediating a crude oil contaminated soil.

Assessment of the Potentials of Water Hyacinth (Eichhornia crassipes) as Raw Material for Biofertilizer

This research investigated the potentials of water hyacinth as raw material for biofertilizers. Water hyacinth was collected from Alape River in Ilaje Local Government Area of Ondo State and processed for microbiological, proximate and physicochemical analyses by standard methods. Results revealed that the total heterotrophic bacterial and fungal populations were 5.0 x 107 (CFU/g) and 3.5 x 105 (CFU/g) and 3.6 x 102 SFU/g and 3.0 x 102 (SFU/g) for root and leaf parts respectively. The population of phosphate solubilizing bacteria, Azospirillum spp., Azotobacter spp. and Rhizobium spp. were 3.5 x 104 - 1.3 x 106 CFU/g, 1.4 x 103- 2.6 x 104 (CFU/g), 3.4 x 103 – 1.7 x 104 (CFU/g) and 1.2 x 103 – 1.1 x 104 (CFU/g) respectively. 16S rRNA gene sequencing revealed the presence of Enterobacter cloacae (LT 221670.1 -53%) and Bacillus safensis (AB711138.1 -99%), Pseudomonas mendocina (LN 881702.1 – 99%) and Aeromonas veroni (LC 487867.1 – 97%) from the root and leaf respectively. Aspergillus spp., Fusarium sp., Rhizopus sp., Trichoderma sp. Cladosporium sp. were among the fungi from the water weed parts. The proximate, nutrient and heavy metal constituents of water hyacinth vary among the leaf, stem and root. The proximate values for moisture (65.45%), protein (12.18%) and carbohydrate (5.30%) were highest in the leaf part compared to the stem and roots. Also, the highest values of ash (18.48%), fat (3.84%) and crude fibre (12.50%) were obtained in the plant root relative to leaf and stem. Apart from magnesium and phosphorous, mineral elements such as sodium, calcium and potassium were more abundant in the leaf. Among the heavy metal, Lead, Cadmium, Nickel, Arsenic and Cobalt had undetectable values for all parts. This study concludes that the presence of microbial biofertilizer and micro and macro nutrients on water hyacinth suggests its potential as raw material for biofertilizer and can be used to promote plant growth without negative consequences.

Interspecific variations in leaf litter decomposition and nutrient release from tropical mangroves

Efficient nutrient cycling through decomposition of leaf litter often regulates the high productivity and subsequent carbon sequestration of mangrove ecosystems along the land-ocean boundary. To understand the characteristics and the potentials of mangrove leaf litter in supplying organic carbon and nutrients to the coastal waters, four major mangrove species (A. officinalis, R. mucronata, H. littoralis and S. apetala) of Bhitarkanika mangrove forest, Odisha, India, were examined in controlled environmental conditions. Half-life time (t0.5), estimated for decomposition of those mangrove leaf litter materials ranged from 18 to 52 days. During the incubation experiment, organic carbon from mangrove leaf litter was released primarily through physical processes and was available for heterotrophic respiration. Among the four species, leaf litter of S. apetala with the lowest initial C/N ratios, released organic carbon with low molecular weight (labile substances) that has a relatively higher potential to support the aquatic food web. On the contrary, leaf litter of R. mucronata released organic material with relatively higher molecular weight (humic substances, higher aromaticity), which revealed its superior non-labile characteristics in this unique environment. The mean total heterotrophic bacterial (THB) population in the incubation was around nine-fold higher than the control. THB population growth and Chromophoric Dissolved Organic Matter (CDOM) spectral data further suggested the rapid release of highly labile and recalcitrant carbon from S. apetala and R. mucronata (between 7th and 21st day of incubation), respectively. The mean litter fall from the Bhitarkanika mangrove forest was estimated to be 11.32 ± 1.57 Mg ha−1 y−1 and its corresponding carbon content was 5.43 ± 0.75 Mg C ha−1. The study revealed the role of leaf litter leachates as an important food source to microbial communities in the adjacent coastal waters, in addition to a potential carbon sequesterer through long-term burial in mangrove soil and export to the deep sea.

Effects of Seasonal Variations on Microorganisms on Paint-Polluted Soil in Nigeria

Adverse impacts of paints effluents from industries improperly disposed into the environment caused pollution, a lot of carcinogenic, mutagenic, physiological alterations resulting in debilitating health effects on humans. The study was aimed at the effects of seasonal variations on soil microorganisms’ dominant at paint effluent disposal sites in lagos. A total of one hundred soil samples each were collected at different seasons of the disposal sites of two paint companies and analysed using standard microbiological methods. Results obtained shows paint effluents caused a significant decrease (p≤0.05) in the population of the microbial groups studied in the different seasons. Total heterotrophic bacterial population decreased from 7.7x108±0.19 to 6.4x107±0.01 in the dry season, and 5.3x108±0.08 to 6.5x107±0.15 during the rainy season. A total of eleven bacterial and eight fungal genera were identified. The identified bacterial genera included Bacillus, Pseudomonas, Staphylococcus, Micrococcus, Serratia, Arthrobacter., Aeromonas, Citrobacter, Alcaligenes, Flavobacterium, and Enterobacter. The fungal genera included Aspergillus, Penicillium, Fusarium, Mucor, Rhodotorula, Cladosporium, Trichophyton, and Geotricum. The most predominant bacteria and fungi were Bacillus (30.0%) and Pseudomonas (16,7%) species and Aspergillus (38.5%) species respectively. This study has confirmed the presence of different microbial species associated with acrylic paint-impacted sites. It, therefore, suggests that improvement of antimicrobial additives of paints may be a promising approach to reduce contamination.

Application of cowdung and sawdust as biostimulants for enhanced bioremediation of diesel contaminated soil

The study was aimed at exploring the use of cow dung (CD) and sawdust (SD) as bio stimulants for enhanced ex-situ bioremediation of diesel fuel contaminated soil. Results of the microbial populations in a gram of soil showed that diesel polluted soil amended with CD had the highest total culturable heterotrophic bacterial (TCHB) population range (1.42 x 106 - 1.56 x 107Cfu/g), total fungal (TF) (1.0 x 106 – 1.60x107Cfu/g), hydrocarbon utilizing bacteria (HUB) (4.5 x 106 – 2.05 x 107Cfu/g) and hydrocarbon utilizing fungi (HUF) (3.5 x 106 – 1.3 x 107Cfu/g) respectively during the study. Diesel polluted soil amended with SD had lower TCHB populations (1.32 x 106 – 2.0 x 107Cfu/g), TF (6.0 x 106 – 3.6 x 107 Cfu/g), HUB (5.4 x 106 – 1.28 x 107Cfu/g) and HUF (1.2 x 106 – 2.0 x 106Cfu/g) respectively, while the microbial populations in option C (control) were TCHB (1.14 x 106 – 1.18 x 107Cfu/g), TF (1.7 x 106 – 7.0 x 106Cfu/g), HUB (4.2 x 106 – 7.8 x 106Cfu/g) and HUF (1.1 x 106 – 5.0 x 107Cfu/g) respectively. Changes in pH values showed reductions in CD (7.10 – 6.20) and SD (5.78 – 4.88) amended soils. Percentage losses in TPH from chromatography results showed diesel polluted soil amended with CD (61.30%), SD (41%) and control (4.11%) respectively. Characterization and identification tests of bacterial isolates revealed that a microbial consortium comprising of the following HUB genera; Bacillus, Pseudomonas, Proteus, Alcaligenes, Klebsiella, Enterobacter, Citrobacter, Corynebacterium and Escherichia coli was implicated in the biodegradation process. Similarly, the HUF encountered were Fusarium, Aspergillus, Microsporium, Penicilium and Mucor. The results suggest that the application of cow dung as biostimulant will enhance the bioremediation of diesel contaminated soil than the application of sawdust.Keywords: Cowdung, Sawdust, Bioremediation, Biostimulation

Comparative Studies on the Bioremediation of Used Engine Oil Contaminated Soil using Urea Fertilizer (UF), Goat Manure (GM), Pig Manure (PM) and Brewery Spent Grain (BSG)

The focus of the study was to evaluate and compare the performance of urea fertilizer, goat manure, pig manure and brewery spent grain for the bioremediation of used engine oil contaminated soil. Soil with no pollution history was collected and subjected to detailed laboratory analysis to determine the total heterotrophic bacterial population, pH, moisture content, total organic carbon, total nitrogen and total hydrocarbon content. Used engine oil contaminated soil was prepared by adding 250g of used engine oil into a clean dry plastic bucket containing 1kg of unpolluted soil. The mixture was properly mixed and covered with aluminium foil paper before use. The used engine oil contaminated soil was left for a period of four (4) days for stabilization before the commencement of treatment. The entire setup and its content was open throughout the period of experimentation to allow for the influence of atmospheric oxidation. The setup was monitored for twelve (12) weeks and sampling/analysis of the samples was done on a weekly basis to ascertain the progress of treatment. The residual hydrocarbon content after each treatment was determined using Atomic Absorption Spectrophotometer. Results obtained shows that pig manure is the best substrate for the clean-up of used engine oil contaminated soil with calculated removal efficiency of 64.4% followed by BSG with 51.4% removal efficiency, Goat Manure with removal efficiency of 39.9% and Urea Fertilizer with 33.7% efficiency. The kinetic modelling shows that experimental data fitted well with pseudo-first order kinetic model with calculated error sum of square (SSE) values of (0.0002, 0.0005, 0.0012 and 0.0072) and root mean square errors (RMSE) of (0.0028, 0.0073, 0.0082 and 0.0481). On the accurate prediction of the optimum remediation time, it was observed that the non-linear regression model gave higher coefficient of determination of 0.9824, 0.9812, 0.9886 and 0.9899 compared to linear regression.

Screening for Hydrocarbon Degrading Bacteria Using Redox Indicator 2, 6-Dichlorophenol Indophenol

Contamination by petroleum products and its derivatives promotes serious environmental damage. Biodegradation capacity studies are important when deciding the correct bioremediation strategy to employ. The use of redox indicator 2, 6-Dichlorophenol Indophenol (DCPIP) is a rapid, simple and low cost model for evaluating capability of microorganisms to utilize and/or degrade petroleum hydrocarbons. This study involved isolation and screening of bacterial species capable of utilizing hydrocarbons from soil at two auto-mechanic workshops in Uyo, Akwa Ibom State. Results of the physicochemical analysis of the soil samples showed higher levels of properties (Moisture content, Organic Carbon content, Total Hydrocarbon Content) in the polluted soil samples when compared with unpolluted (control) soil sample. Total heterotrophic bacterial populations in polluted soil samples ranged between 4.4±1.90x10 7 and 6.0±32.0x10 7 CFU/g while hydrocarbon utilizing bacterial counts were between 3.2±0.05x10 7 and 5.2±25.2x10 7 CFU/g. Eight bacteria species capable of utilizing petroleum were isolated from these soils by enrichment technique. Isolated bacteria include: Corynebacterium spp, Pseudomonas aeruginosa, Micrococcus agilis, Flavobacterium aquatile, Staphylococcus aureus, Micrococcus luteus, Serratia odorifera and Bacillus substilis . Screening of bacterial isolates for efficiency in hydrocarbon utilization using DCPIP, measured by using colorimetry, revealed Bacillus substilis, Pseudomonas aeruginosa, Micrococccus agilis, Flavobacterium aquatile Micrococcus luteus and Corynebacterium spp to be able to rapidly utilize hydrocarbons from waste engine oil.

Changes in the physicochemical and microbial quality of wastewater from a wastewater treatment plant

The discharge of wastewater directly into the environment could constitute serious health hazards to humans and other life forms. This study aimed at determining the changes in the physicochemical and bacteriological quality of wastewater from a treatment process plant. Wastewater samples were aseptically collected at 10 different points of a treatment plant and bacterial isolates were obtained from them. Isolates were identified using biochemical technique and API 20E identification system. The isolates were assessed for resistance to common antibiotics using Kirby-Bauer disk diffusion method from which the Multiple Antibiotic Resistance (MAR) Index was calculated. There was improvement in the physicochemical parameters analyzed. The biological oxygen demand, dissolved oxygen, pH, temperature, turbidity, salinity, sulphate and heavy metal concentrations were within acceptable wastewater effluent limits at point of discharge. The total heterotrophic bacterial population, total coliforms and total heterotrophic fungi ranged from 1.4 x 107 to 4.0 x 102 , 3.2 x 104 to 2.0 x 10 2 and 5.6 x 104 to 2.5x 102 cfu ml -1 at the point of entry and discharge to the environment respectively. Thirteen bacterial species were detected from the wastewater samples collected which include Enterobacter species (3), Escherichia spp. (3), Klebsiella species (3), Enteric group 69 (1), Rahnella aquatilis (1), Edwardsiella tarda (1) and Buttiauxella ferraguitiae (1). None of the isolates had 100% susceptibility to the antibiotics investigated. The most prevalent multiple antibiotic resistance phenotype observed among the isolates were tetracycline, gentamicin and cotrimoxazole. The MAR values ranged from 0.16 to 0.83. The result proved that the treatment process was effective in reducing the final concentrations of the physicochemical parameters, microbial load and pathogen discharged into the environment. Keywords: Antibiotics, coliforms, metals, physicochemical, wastewater.

Removal of phosphate by Staphylococcus aureus under aerobic and alternating anaerobic–aerobic conditions

ABSTRACTEutrophication of water bodies due to phosphate enrichment is an ecological problem. Phosphate is removed from wastewaters by enhanced biological phosphate removal worldwide by phosphate accumulating organism. In order to understand the process of treatment, the existing microbial community and its metabolism of phosphate removal are studied widely. This study focuses on the isolation of polyphosphate-accumulating bacteria from different environments and studying their phosphate removal capacity with different carbon supplements under varying culture conditions. The total heterotrophic bacterial population from the diverse environments showed the existence of phosphate-accumulating bacteria. Among them, Staphylococcus aureus removed 81% of phosphate in a polyphosphate-accumulating medium with storage of 93 mM polyphosphate internally. Among the different carbon sources provided, glucose induced a net specific growth rate of 0.816/d. S. aureus removed 70% of phosphate with a phosphate uptake rate of 6.29 mg PO4/g cells and a growth yield of 0.2 g cells/g glucose consumed when 1 g/L glucose was provided. Furthermore, when 2 g/L glucose was provided, 78% of phosphate was removed with a phosphate uptake rate of 13.24 mg PO4/g cells and a growth yield of 0.4 g cells/g glucose consumed under aerobic condition. S. aureus showed enhanced phosphate removal under aerobic condition in the presence of glucose.

English

A total of ten soil samples were collected from four different dump sites in Port Harcourt Metropolis. The samples were examined for temperature, pH, total heterotrophic bacterial and fungal counts. The mean temperature values of the soils ranged from 27 to 28°C while the mean pH values ranged from 6.5 to 7.8. The total heterotrophic bacterial population ranged from 2.4 × 107 to 1.2 × 108 cfu/g while total fungal population ranged from 4.8 × 106 to 2.3 × 107 cfu/g. The bacteria population isolated from the waste dump sites were: Bacillus, Escherichia coli, Klebsiella, Proteus, Pseudomonas, Staphylococcus and Streptococcus species while the fungi included Aspergillus, Fusarium, Mucor, Penicillium and Saccharomyces species. The results showed that there was significant difference at 0.05 confidence limits between the pH levels at R(Ra:R1,R2; Rb:R3,R4) and U ( Ua:U1,U2; Ub: U3,U4). There was no significant difference at 0.05 confidence limits between the temperature levels, total heterotrophic bacterial and fungal counts at sites R and U. In dump sites R and U, there were no significant differences between the bacterial and fungal counts obtained in both sites.    Key words: Dump sites, Port Harcourt metropolis, bacteria and fungi. &nbsp

English

Availability of heterotrophic soil bacteria and an associative micro-aerophilic nitrogen fixing Azospirillum, from the rhizosphere of different crop plants, was studied. Microorganisms were reported from root and rhizospheric soil (from twenty-seven different samples collected from Chhattisgarh, India) of different crop plants. The amount of total heterotrophic bacteria, in different samples, varied significantly from 3.01×108 to 4.90×108 in rhizosphere and from 1.11×108 to 2.91×108 in root tissues. Azospirillum population significantly varied from 3.81×108 to 4.90×108 in rhizosphere and from 2.09×108 to 2.88×108 in root tissues. Rhizospheric soils were found to harbor the highest population of heterotrophic soil bacteria and Azospirillum in comparison with plant tissues. Nitrogen, phosphorus, potash, organic matter (OM) and pH value have significant positive correlation but electrical conductivity (EC) have non-significant effect with total heterotrophic bacterial population. Based on the correlation co-efficient (r) value, all significant positive correlation has been grouped in three categories viz; strong (r = >0.5), medium (r = >0.4 but <0.5) and weak (r = <0.4). Thus, in the present study, N, OM and rhizospheric pH have strong significant positive correlation with total heterotrophic bacterial population while P and K content have medium correlation with bacterial population.   Key words: Heterotrophic bacteria, rhizosphere, Azospirillum, nitrogen fixing bacteria, correlation, regression.

The distribution and diversity of culturable aerobic heterotrophic benthic bacteria in the continental slope of the Bay of Bengal: Linked abiotic factors, including a tsunami

The culturable aerobic heterotrophic benthic bacterial population and community structure in relation to the physico-chemical parameters in the continental slope of the Bay of Bengal was studied. In addition, diversity indices were calculated and pretsunami (in 2004) and post-tsunami (in 2005) diversity values were compared. Sediment samples were collected from two cruises in the depth zone of 214–1000 m (10°36′ N–20°01′ N and 79°59′ E–87°30′ E). The vertical distribution of the total heterotrophic bacterial population during both cruises was higher in the top section (0–3 cm) of the sediment. The average total heterotrophic bacterial population was in the range of 0.42–37.38 × 104 CFU/g to 1.66–19.73 × 104 CFU/g dry sediment weight during the two cruises, respectively. The limiting physico-chemical factors were sediment pH, sediment temperature, TOC, porosity, and clay as revealed from multiple regression (r = 0.75) and BIOENV (Partial Correlation ρω = 0.447) analyses. The shannon-Wiener index (H′ log e), Simpson index (D), Margalef index (d) and Pielou’s evenness index (J′) were found to be higher in the 1000 m depth stations. Cluster analysis showed that the 500 m depth stations clustered either with the 200 m or with the 1000 m stations. The 200 m depth stations never formed a cluster with the 1000 m stations. Pre-tsunami diversity indices at two depth ranges (200 m and 1000 m) were higher than those of the post-tsunami indices, which was quite evident from the cluster analysis as well. This study confirms the effect of the tsunami surge in the sediments of the continental slope of the Bay of Bengal in the marine ecosystem, which is also attributed to the temporal variation of the heterotrophic bacterial population and diversity.

English

Shells of crabs are infected with a high prevalence of diseases than any other crustacean. Bacteria, viruses, fungi and several other pathogens influence higher percentage of shell disease in crabs. Infections in crab affected growth and metabolism and it may also lead to death. This work deals with the microscopic examination of shell diseased crabs with reference to its variation in hemocytes count, histopathology and biochemical estimation. The total heterotrophic bacterial (THB) population in normal shell was found to be 5.15 x 104 ± 0.09 Colony forming unit (CFU) ml-1 and THB load was noted to be slightly increased than in normal shell and the count was 5.95 x 104 ± 0.12  CFU ml-1 in the infected shell. The current findings suggest a positive correlation between bacterial shell disease and the secondary infection affecting hemolymph (total hemocyte count), proximate composition (protein, carbohydrate and lipid) and histopathology of the animal (gills, hepatopancreas and heart). The total hemocyte count and differential count were experimented which showed lower number of total hemocytes in infected crabs while no highly accountable difference was found in differential count. Hematology studies reported total hemocyte as 9.93 x106 ± 0.07 cells ml-1 in normal and 6.525 x 106 ± 0.12 cells ml-1in shell diseased hemolymph. The level of protein, carbohydrate and lipid contents suffered a mild alteration in crabs with bacterial shell disease. Histopathology of gills hadshown variations such as dilated lamellae and hemocyte accumulation (nodules), hepatopancreas showed mild difference with increased necrosis, appearance of hemocytic nodules in the hemal spaces and heart with very mere infection while no reportable changes were accomplished in muscle tissue.   Key words: Shell disease, bacteria, hematology, histopathology, biochemical composition.

EVALUATION OF PHYSICO -- CHEMICAL PARAMETERS AND MICROBIOLOGICAL POPULATIONS OF CAUVERY RIVER WATER IN THE PALLIPALAYAM REGION OF TAMIL NADU, INDIA

The present investigation was carried out to evaluate physico-chemical parameters and total heterotrophic bacterial and fungal populations from Cauvery River water in the Pallipalyam region during the period from January 2009 to December 2009 . Physicochemical parameters were analyzed using APHA standard procedure and microbiological count done by standard pour plate technique. The Physico-chemical parameters like temperature, hydroxyl ionic concentration (pH), electrical conductivity recorded were in a range of 24.7 - 29 C o , 7.5 - 9.2, and 406 - 982 µS/cm respectively. Besides, turbidity, Dissolved Oxygen (DO), Total Dissolved Solids (TDS), Total Suspended Solids (TSS ), Total hardness and Total alkalinity of river water samples recorded were in the ranges of 7 – 11 NTU, 5 - 12mg/L, 291-701mg/L , 3 - 5mg/L, 228-364mg/L, and 139 - 245mg/L respectively. Nitrite, Phosphate, Chemical Oxygen Demand (COD) and Chloride of the river water exhibits within the ranges of 0.012 - 0.102 mg/L, 0.019 -.023 mg/L, 41.08 - 77.24 mg/L, and 53.56 - 143.16 mg/L respectively. A calcium and magnesium levels of the water samples during the study period were analyzed and the results recorded were in the ranges of 57.31 - 101.4 mg/L and 27.22 - 57.35 mg/L respectively. The amount of Sodium, Potassium and Ammonical nitrogen of the water samples estimated were in the ranges of 35.44 - 88.57 mg/L and 3 - 8 mg/L, 5.83 and 3.26 mg/L respectively. Bicarbonates and carbonates levels analyzed during the study period recorded were in the ranges of 164.7-303.78 mg/L and 2.4 - 9.6 mg/L respectively. The total bacterial and fungal populations were recorded during the study period. The maximum and minimum values of population density were ranged between 4.3 - 0.5 X 10 3 CFU/ml, and 3.2 - 0.1 X 10 3 CFU/ml respectively. The values of Physico-chemical parameters recorded were indicated that, the river was polluted in terms of increased accumulation of xenobiotics compounds by anthropogenic activities .The immediate attention from the concerned authorities is required to protect river from further pollution.

Membrane bioreactor treatment of commonly used organophosphate pesticides

Five pesticide formulations registered for use in Canada containing organophosphate-insecticide active ingredients azinphos-methyl, chlorpyrifos, diazinon, malathion and phorate were subjected to treatment by membrane bioreactor (MBR) technology. The target active ingredients were introduced to the MBR at ppm level concentrations. The biodegradation of these compounds was analyzed daily using selected ion monitoring gas chromatography−mass spectrometry (GC/MS-SIM) following extraction of the analytes using solid-phase extraction (SPE). Amounts measuring 83 % to 98 % of the target analytes were removed with steady-state concentrations being reached within 5 days of their introduction. The dissolved oxygen, temperature, pH, and total heterotrophic bacterial population were monitored daily to ensure optimal conditions for biodegradation. The quality of the effluent from the MBR was assessed daily through spectrophotometric methods. Measurements were conducted for the concentration of ammonia, nitrate, nitrite, total and reactive phosphorus, as well as the chemical oxygen demand (COD) of the effluent. This study demonstrated that the MBR technology is feasible and efficient for treatment of organophosphate pesticides without introducing additional chemical additives.

HYDROCARBON-DEGRADING BACTERIA ASSOCIATED WITH INTESTINAL TRACT OF FISH FROM THE BALTIC SEA / ANGLIAVANDENILIUS SKAIDANČIOS BAKTERIJOS BALTIJOS JŪROS ŽUVŲ VIRŠKINAMUOSIUOSE TRAKTUOSE / УГЛЕВОДОРОД РАСЩЕПЛЯЮЩИЕ БАКТЕРИИ В ПИЩЕВАРИТЕЛЬНОМ ТРАКТЕ РЫБ БАЛТИЙСКОГО МОРЯ

The hydrocarbon-degrading bacterial diversity of the intestinal tract content of fish – the Baltic cod (Gadus morhua), plaice (Platichthys flesus) and the Baltic herring (Clupea harengus) – from the Baltic Sea has been investigated by molecular methods: DNA extraction, amplification polymerase chain reaction product and sequencing of partial 16S rRNA genes. The results of this study show that dense total heterotrophic bacterial populations occur in the intestinal tract of investigated fish. The data obtained showed that the abundance of hydrocarbon-degrading bacteria in the intestinal tract of fish varied from 2.40×104 to 1.08×105 cfu g–1between fish species and was still high. Phenotypic examination of the recorded hydrocarbon-degrading bacteria from the intestinal tract of the Baltic cod, plaice and the Baltic herring revealed that they belong to Aeromonas, Pseudomonas/Shewanella. Molecular species of hydrocarbon-degrading bacteria found in the digestive tract of fish from the Baltic Sea were: Aeromonas veronii, Aeromonas sobria, Shewanella spp. and Acinetobacter spp. We argue that hydrocarbon-degrading bacteria in intestinal tract of fish take part in purification processes, as well as, bacteria in water and play a role in adaptation and survival of fish chronically exposed to pollution with hydrocarbons. Santrauka Angliavandenilius skaidančių bakterijų įvairovė Baltijos jūros žuvų – menkių (Gadus morhua), plekšnių (Platichthys flesus) ir strimėlių (Clupea harengus) žarnynų turinyje tirta molekuliniais metodais: DNR išskyrimas, polimerazės grandininės reakcijos produkto amplifikacija ir 16S rRNR genų sekvenavimas. Tirtų žuvų žarnynuose nustatytos gausios heterotrofinių bakterijų populiacijos. Angliavandenilius skaidančios bakterijos išskirtos iš visų tirtų žuvų žarnynų turinio. Jų kiekis žuvų žarnynuose svyravo nuo 2,4×104 iki 1,08×105 kfv (koloniją formuojantis vienetas) ir buvo pakankamai didelis. Fenotipiniais bakterijų identifikavimo metodais nustatyta, kad angliavandenilius skaidančios bakterijos, išskirtos iš Baltijos jūros žuvų žarnynų turinio, priklausė Aeromonas Pseudomonas/Shewanella gentims. Molekuliniais metodais nustatyta, kad angliavandenilius skaidančios bakterijos tirtų žuvų žarnynuose yra Aeromonas sobria, Aeromonas veronii, Shewanella spp. ir Acinetobacter spp. Galima daryti prielaida, kad žuvų žarnynuose gyvenančios angliavandenilius skaidančios bakterijos dalyvauja savivalos procesuose kaip ir vandenyje gyvenančios bei angliavandenilius skaidančios bakterijos ir padeda adaptuotis ir išgyventi žuvims vandenyse, pastoviai teršiamuose nafta ir jos produktais. Резюме Разнообразие углеводородрасщепляющих бактерий в содержимом кишечника рыб: трески (Gadus morhua), камбалы (Platichthys flesus ) и салаки (Clupea harengus) из Балтийского моря было исследовано молекулярными методами: выделение ДНК, амплификация ПЦР продукта, секвенация 16S рРНК генов. В кишечнике исследованныхрыб найдены многочисленные популяции гетеротрофных бактерий. Углеводородрасщепляюшие бактерии выделены из содержимого кишечника всех исследованных рыб. Их численность колебалась в пределах 2,4×10 4 – 1,08×10 5 КФЕ (колонию формирующая единица) и была достаточно высокая. Фенотипическими методами идентификации бактерий установлено, что углеводородрасщепляюшие бактерии из пищеварительного тракта рыбпринадлежали родам Aeromonas и Pseudomonas/Shewanella. Молекулярными методами определено, что углеводородрасщепляюшие бактерии из пищеварительного тракта рыб принадлежали видам Aeromonas sobria, Aeromonas veronii, Shewanella spp., Acinetobacter spp. Можно предположить, что углеводородрасщепляющие бактерии из пищеварительного тракта рыб участвуют в процессах самоочищения, как и бактерии, обитающие в водной среде, атакже помогают адаптироваться и выжить рыбам в водах, постоянно загрязняемых нефтью и ее продуктами.

Use of different microbial probiotics in the diet of rohu, Labeo rohita fingerlings: effects on growth, nutrient digestibility and retention, digestive enzyme activities and intestinal microflora

Six iso-nitrogenous (350 g protein kg−1) and iso-caloric (4100 kcal kg−1) diets with or without probiotics supplementation namely T1 (Basal feed (BF) without probiotics; control), T2 (BF + Bacillus subtilis and Lactococcus lactis), T3 (BF + L. lactis and Saccharomyces cerevisiae), T4 (BF + B. subtilis and S. cerevisiae), T5 (BF + B. subtilis, L. lactis and S. cerevisiae) and T6 (BF + heat-killed bacteria of B. subtilis, L. lactis and S. cerevisiae) were fed to Labeo rohita fingerlings (6.0 ± 0.06 g) for 60 days in triplicate tanks (30 fish per tank). In all probiotic-supplemented diets, the probiotic concentration was maintained at 1011 cfu kg−1 feed. After 60 days of culture, the fish fed combination of three probiotics at equal proportion (T5) had higher (P < 0.05) growth, protein efficiency ratio, nutrient retention and digestibility and lower (P > 0.05) feed conversion ratio over other treatment groups. Total heterotrophic bacterial population in intestine was drastically reduced on 15th and 30th days of sampling than the initial value (0 day of sampling) for T3, T4 and T5 groups. Except T6, the gut colonization of respective probiotics, which were supplemented through the diets, was also increased up to 30 days of culture of fish and thereafter remained constant.

Ecology Of Total Heterotrophic Bacterial Population From Rameswaram Island(Palk Bay) Southeast Coast Of India

Ecology Of Total Heterotrophic Bacterial Population From Rameswaram Island(Palk Bay) Southeast Coast Of India

Gut microbiota of crabs from the Vellar estuary, southeast coast of India

Animals in the aquatic environment carry a particular bacterial flora that is a reflection of their environment. In the present study the level of total heterotrophic bacterial (THB) populations observed in the gut of crabs simply reflected the THB in the water and sediment of the environments from which the crabs were collected. Crabs were collected from the different areas, i.e. neritic, mangrove and oyster zones, of the Vellar estuarine environment of the southeast coast of India. THB populations were high in the water and sediment in the mangrove and neritic zones. Among the three stations, less bacterial populations were observed in the water, sediment and the gut of the crabs in the oyster zones due to the constant disturbance of wave action from the estuarine mouth region. Bacteria belonging to the genera Pseudomonas and Vibrio were found to be higher in all the three different stations. In the mangrove region, Bacillus was the dominant genus in sediment samples. Key words: Gut microbiota, crabs, neritic zone, oyster zone, mangrove zone

Microbial diversity in firework chemical exposed soil and water samples collected in Virudhunagar district, Tamil Nadu, India

Microbial diversity of soil and water samples collected from pyrochemicals exposed areas of Virdhunagar district (Tamil Nadu, India) was studied. Soil and water samples from cultivable area, waste land and city area of the same region were also studied for a comparative acount. There is a remarkable reduction in total heterotrophic bacterial population (THB) in pyrochemicals exposed soil and water samples (42 × 10(4) CFU/g and 5.6 × 10(4) CFU/ml respectively), compared to the THB of cultivable area soil and water samples (98 × 10(7) CFU/g and 38.6 × 10(7) CFU/ml). The generic composition the THB of the pyrochemicals exposed samples too exhibited considerable change compared to other samples. Pseudomonas sp. was the predominant one (41.6%) followed by Achromobacter sp. (25%) in pyrochemical exposed soil and Pseudomonas sp. was the predominant one (25%) in pyrochemical exposed water samples followed by Bacillus sp. (25%) and Micrococcus sp. (16.6%). It was observed that Cornybacterium sp. and Micrococcus sp. were absent completely in pyrochemical exposed soil and Achromobacter sp. was missing in the pyrochemical exposed water samples, which were present in the other samples. The outcome of this study clearly demonstrates that pollutants such as chemicals used in pyrotechniques affect the microbial biodiversity and suitable measures have to be taken to control the pollution level and to save biodiversity.