Counts Of Heterotrophic Bacteria Research Articles

Influence of various carbon and nitrogen ratios in a jaggery-based biofloc rearing system on the Asian stinging catfish Heteropneustes fossilis

Biofloc technology (BFT) is becoming popular in aquaculture. As the human population has rapidly increased, so has the demand for protein, driving the expansion of aquaculture. The increased use of aqua medicines in aquaculture has led to resistant microbes. BFT offers a promising, eco-friendly solution by promoting beneficial microbes to improve fish health and reduce chemical use, supporting the industry's long-term sustainability. BFT recycles waste without water exchange by maintaining an optimal carbon-nitrogen (C:N) ratio and adding an external carbon source, which promotes the growth of heterotrophic bacteria and other essential microbes that absorb ammonia from feed and waste, forming beneficial microbial aggregates. This study evaluated the effects of various C:N ratios in a jaggery-based BFT system on water quality, growth, feed efficiency, and the well-being of Heteropneustes fossilis. A completely randomized design with triplicates (2.33 kg/m³ in 1500 L tanks) was used to compare a control group without biofloc to three BFT treatments with C:N ratios of 8:1 (CN8), 12:1 (CN12), and 16:1 (CN16) over 180 days. Daily feeding was conducted at 5–2 % of the fish's body weight (initial weight of 5.0±0.5 g). Higher C:N ratios were linked to reduced dissolved oxygen, ammonia, and nitrite levels, alongside increased total suspended solids, floc volume, and heterotrophic bacteria counts, while the CN12 had the highest levels of beneficial microbes (Firmicutes and Actinobacteria), leading to superior fish growth, survival, and biomass compared to CN8 and CN16. The CN12 also showed better stress response, hematology, immunity, and antioxidant properties. Histologically, fish in CN12 and CN8 had healthier liver and intestines compared to CN16 and control. The results suggest that a C:N ratio of 12:1 was optimal for biofloc systems used in cultivating H. fossilis, enhancing both microbial growth and water quality.

Physiochemical and Microbial Quality of Melon and Bush Mango Seeds and Milled Products in Local Markets ln Rivers State,Nigeria.

Risk of food borne infection contamination of food, in Africa is increased due to environmental, agronomic and socio-economic factors. This study assesses the microbial quality of melon and bush mango displayed in the local markets, aiming to provide valuable insights into the safety and quality of these widely consumed food products. Standard procedure for microbiological and proximate analysis were employed. The heterotrophic bacteria count ranged from 8.5 x 10⁵ cfu/g to 1.35 x10⁶ cfu/g. The total staphylococcus count ranged from 1.2 x 10³ cfu/g to 4.35 x 10³ cfu/g. The coliform count ranged from 2.8 x 10⁴ to 7 x 10⁵, Total Samonella count ranged from 4 x 10² cfu/g to 1.5 x 10³ cfu/g and Fungi count 6.5 x 10² cfu/g to 2.5 x 10³ cfu/g. Morphological and Biochemical characterization of heterotrophic bacteria isolated from both melon and bush mango identified nine genera, including Staphylococcus (14.6%) Bacillus (20%), Corynebacterium (5.6%) Enterobacter (4.4%), Micrococcus ( 3.3%) Pseudomonas (12.2%), Escherichia coli (13.3%), Salmonella (11.1%) and Proteus (11.1%). Fungal species like Penicillium spp., Fusarium spp., Aspergillus flavus, Candida spp., Mucor spp., Saccharomyces sp., and Aspergillus niger were isolated from both seed and milled seeds samples of melon and bush mango. The frequency of occurrence revealed variations among bacterial isolates in melon and bush mango seeds. The most frequent fungal species included Candida spp. (9.4%) Aspergillus niger (20%) Mucor (9.4%), Fusarium (11.4%), Aspergillus flavus (9.4%), Penicillium (13.2%), Rhizopus spp (3.7%) and Saccharomyces (15%). Proximate and heavy metal analysis indicated variations in the composition of Carbohydrate (7.11%), Lipid (15.03%), Ash (1.89%), Moisture (7.31%), Protein (23.86%), Crude Fiber (12.66%), Lead (0.213 mg/kg), Copper (2.11mg/kg), calcium (0.49mg/kg) and Cadmium (0.0169mg/kg) in melon and bush mango, Carbohydrate (15.03%), Lipid (58.24%), Ash (1.74%), Moisture (10.48%), Protein (11.95%), Crude Fiber (2.64%), Lead (1.7903mg/kg), Copper (2.11mg/kg), calcium (0.148mg/kg) and Cadmium (0.000385mg/kg). The presence of heterotrophic bacteria in such ranges suggests potential differences in hygiene practices during cultivation, processing, and storage. Therefore; Implement stringent quality control measures during the production, processing, and storage of both melon and bush mango seed.

Hydrocarbon Degradation and Biodegraders in Oil Spillage Sites in Port Harcourt

Information on remediation of soils polluted from the activities of artisanal crude oil refining is lacking. The functional capability of the indigenous microbial community and prospects for recovery of important bio-resources has also not been explored. The aim of this study was to identify the hydrocarbon biodegrader present in oil spillage sites in Port Harcourt. Samples were taken from various sites (labelled ss1, ss2, ss3 and controls) in Port Harcourt and the samples were transported to the lab for bacteriological assessment. The samples were cultured in Nutrient agar and Basal Salt Medium (BSM). The total heterotrophic bacteria counts were enumerated by serially diluting the fluid sample. Microbial characterization was done based on morphological, physiological and biochemical tests. From the results, Pseudomonas species and Bacillus species were the probable isolated from the culture of hydrocarbon contaminated environment. The results also revealed increased compared to the control organism that maintained the same growth level throughout the 5 days of incubation, the isolated bacteria (Pseudomonas species and Bacillus species) had steady bacterial growth. This study has shown that Bacillus species and Pseudomonas aeroginosa are potential agents of bioremediation of environmental hydrocarbon pollution.

Fungal and bacterial evaluation in drinking water distribution network and their association with physicochemical parameters

Preventing the growth of microorganisms in water distribution network (WDN) is an important public health priority. In this study, 98 water samples were collected from the Gorgan City (Iran) water distribution network (WDN) to assess fungal and bacterial contamination in WDN and their association with physicochemical parameters. All microbiological and physicochemical tests were performed as described in the standard method. The results showed that 15.3 %, 12.2 %, and 2 % of the sample had total coliforms, Clostridium perfringens and fecal coliforms, respectively; however, no Escherichia coli and fecal streptococci were found in samples. The average count of heterotrophic bacteria and fungi was 203.45 CFU/mL and 6.83 CFU/100 mL, respectively. Seven genera of fungi were isolated, of which Candida (19.4 %) and Aspergillus (11.2 %) were the most prevalent, followed by Penicillium (5.1 %), Rhodotorula (3.1 %), Cladosporium (2 %), Acremonium (2 %) and Alternaria (1 %). The mean and Standard deviation of free residual chlorine (FRC), pH, turbidity, temperature, total organic carbon and electrical conductivity were 0.22 ± 0.27 mg/l, 7.28 ± 0.22, 0.61 ± 0.68 NTU, 19.27 ± 2.83 °C, 0.45 ± 0.17 mg/l, and 953.49 ± 207.54 (µs/cm), respectively. The presence of pathogens fungus is a major public health concern for people with lowered immunity. The present study indicated that using microorganisms with different features provides a more reliable evaluation to assess the microbial growth in WDN. Amongst physicochemical parameters, FRC above 0.8 mg/l prevented the fungal and bacterial pathogens growth in WDN. However, further research is required to measure the risks of trihalomethane formation.

Proximate and microbial quality of processed grubs of African palm weevil (<i>Rhynchophorus phoenicis</i> F., Coleoptera: Curculionidae) sold at Toru-Orua, Bayelsa State, Southern Nigeria

The African palm weevil, Rhynchophorus phoenicis F. (Coleoptera: Curculionidae) constitutes a significant component in diets of the Niger Delta of Nigeria. This study aimed to determine the proximate composition and microbiological quality of processed grubs (steamed, dried, fried and fresh which served as control) purchased from food vendors in Toru-Orua community. Proximate composition determinations followed official methods recommended by the Association of Official and Analytical Chemicals (AOAC), while microbial load was determined by total plate count. Steamed grubs had the highest moisture content of 15% while fresh had the least moisture content of 9.3%. Steamed grubs had the highest ash content of 11.47% while fresh had the least ash content of 4.73%. Fresh grubs had the highest crude protein of 41.75% while fresh had the least crude protein of 30.13%. Steamed grubs had the highest crude fibre content of 18.07% while fresh had the least crude fibre of 13.7%. Steamed and fried grubs had the highest crude fat content of 10.93% while fresh had the least crude fat content of 2.8%. Steamed grubs had the highest moisture content of 28.35% while dried grubs had the least moisture content of 20.66%. The total heterotrophic bacteria count ranged from 8.5 x 102 CFU/g – 3.7 x 106 CFU/g. Fungal count ranged from 2.2 x 102 - 3.4 x 103 CFU/g. The microbial investigations showed Pseudomonas aeruginosa, Escherichia coli and Staphylococcus aureus were the common microorganisms on the grubs. Frequent microbiological quality checks on such ready-to-eat foods, along with public enlightenment campaigns for food vendors is recommended, to guarantee food safety for consumers during processing/handling, storage and consumption.

Physical-chemical and microbiological characterization of water destined to hemodialysis

This research evaluated the physical-chemical and microbiological parameters of water and dialysate in four distinct hemodialysis units located in the southeast region of Brazil. The physical-chemical parameters evaluated were pH, electric conductivity, turbidity, alkalinity, free chlorine, nitrate, fluoride, chloride, sulfate, sodium, potassium, calcium, and magnesium ion concentrations. Microcystin was also quantified. The microbiological parameters evaluated were the detection of total coliform, total heterotrophic bacteria count (THB), and the isolation and identification of microorganisms in pre-reverse osmosis treatment and post-reverse osmosis treatment water samples and dialysate. The nitrate, fluoride and THB levels found in the water samples may present risk to the patient under hemodialysis treatment. Microcystin was detected in one of the potable water samples. Microorganisms were identified throughout the hemodialysis of the entire water treatment system, with Ralstonia sp. being the most frequent. The presence of emergent pathogenic bacteria highlighted in this study highlights the necessity of microbiological monitoring of water destined for hemodialysis. Keywords: dialysate, hemodialysis, water treatment.

OCCURRENCE OF VIRULENCE GENES OF Staphylococcus aureus AND Escherichia coli IN VENDED FOODS IN SELECTED MOTOR-PARKS IN OBIO/AKPOR, RIVERS STATE

The study aimed at evaluating the microbiological safety of vended foods in selected motor parks in Obio/Akpor Local Government Area, Rivers State, Nigeria. Forty-eight samples obtained from four motor parks (Choba, Rumuokoro, Eliozu and Oil-mill Park) were analyzed using standard microbiological methods for total heterotrophic bacteria count, virulent and antibiotic resistant profiles of Staphylococcus aureus and Escherichia coli. Total heterotrophic bacteria count ranged from 4.60 to 8.39 log10CFU/g. A total of 10 (20.83%) samples were positive for S. aureus while 14 (29.17%) were positive for E. coli. Total staphylococcal and Escherichia coli counts ranged from 4.89 to 7.01 and 2.70 to 5.31 log10cfu/g, respectively. Both bacteria were 100% resistant to augmentin. The confirmed E. coli showed varying resistant to cefixime (50%), ceftazidime (42.86%), cefuroxim (14.29%) and ofloxacin (7.14%); while S. aureus also showed varying resistant to erythromycin (10.00%), ceftriaxone (90.00%), cloxacillin (100.00%) and gentamycin (0.00%) The confirmed E. coli produced the expected bands for the E. coli attaching and effusing (eaeA), aggregative adherence fimbriae (aggR) and antimicrobial sensitivity testing (astA) virulence genes while S. aureus did not produce the expected bands with staphylococcal enterotoxin A (sea) and staphylococcal enterotoxin B (seb) genes. The detection of virulence gene bearing E. coli and multiple antibiotic resistant E. coli and S. aureus portends danger for commuters who patronizes these foods, hence the need for urgent public health interventions.

Impact of Some Hair Cream Compositions on the Flora Density of Human Scalp

The study assessed the effect of some brands of hair creams coded MBB and SDR on the flora density of the human scalp in parts of Port Harcourt. Twenty volunteered persons subjected their scalp aseptically; for swap collection before and after application of the coded hair creams. Standard microbiological procedure was adopted to culture the scalp samples on prepared sterile nutrient agar, mannitol salt agar, MacConkey agar and Sabouraud destrose agar media. All the inoculated culture media plates were incubated in their respective temperature requirements and after which colonies that developed were counted. The result showed heterotrophic bacteria counts of 9.8 x 103 and 9.3 x 103CFU/ml for before and after application of SDR hair cream, while counts of 1.05 x 104 and 1.07 x 104CFU/ml were obtained from MBB hair volunteers before and after application respectively. Similarly, a Staphylococcal count of 4.5 x 103 and 3.7 x 103CFU/ml were obtained before and after application of SDR hair cream, while counts of 6.2 x 103 and 5 x 102 CFU/ml were obtained from MBB hair before and after application respectively. A total of 53 isolates were recovered from which two bacteria genera namely: Staphylococcus epidermidis, Staphylococcus aureus and a fungi genera named Candida krusei were identified. Staphylococcus aureus and Staphylococcus epidermidis were noted with a 12% and 56% occurrence respectively, in sample SDR volunteers. MBB cream volunteers, recovered 14.8 and 7.4 % frequency occurrence for Staphylococcus epidermidis and Staphylococcus aureus respectively. Thus, a negative effect of hair cream SDR on the human scalp was observed. The SDR hair cream significantly, reduced the Staphylococcal normal flora of the scalp, which can lead to the development of opportunistic infection. The study recommends that users of SDR cream to be mindful in application due to creams composition.

Occurrence of coliforms and biofilm-forming bacteria in raw, treated, and distributed water from two waterwork systems in Osun State, Southwestern Nigeria.

This study assessed the bacteriological quality of raw, treated, and distributed water from Ede-Erinle and Opa reservoirs in Osun State, Nigeria. This was to determine the potability of water from these waterwork stations. Eighteen sampling points were established across the two reservoir networks for this study. Samples were collected bi-monthly for two annual cycles. Serial dilution and pour plate methods were employed for the enumeration of bacterial load. Total heterotrophic bacteria count (THBC) and total coliform bacteria count (TCBC) were enumerated on nutrient and MacConkey agar at 37 °C, respectively. Bacterial isolates were characterized using biochemical identification methods with reference to Bergey's Manual of Determinative Bacteriology. Bacterial isolates and biofilm formation were further identified molecularly through the PCR method using specific universal primers. Mean values of THBC and TCBC in distributed water from Ede-Erinle (9.61 × 104 ± 1.50 × 104 CFU/mL; 69.56 ± 26.81 CFU/mL) and Opa waterworks (9.58 × 104 ± 2.55 × 104 CFU/mL; 142.94 ± 44.41 CFU/mL) exceeded permissible limits for drinking water. Paenibacillus lautus, Bacillus pseudomycoides, Pseudomonas aeruginosa, and Pseudomonas stutzeri showed biofilm-forming capacity. The study concluded that the presence of coliforms and biofilm-forming bacteria in distributed water implies that the water is unfit for consumption without further treatment.

Comparing the Effects of Two Culture Methods to Determine the Total Heterotrophic Bacterial Colony Count in Hospital Purified Water

BackgroundAccurately detecting the quantity of microorganisms in hospital purified water is of significant importance for early identification of microbial contamination and reducing the occurrence of water-borne hospital infections. The choice of detection method is a prerequisite for ensuring accurate results. Traditional Plate Count Agar (PCA) belongs to a high-nutrient medium, and there may be limitations in terms of accuracy or sensitivity in detecting microorganisms in hospital purified water. On the other hand, Reasoner’s 2A agar (R2A) has characteristics, such as low-nutrient levels, low cultivation temperature, and extended incubation time, providing advantages in promoting the growth of aquatic microorganisms. This study, through comparing the differences in total colony counts between two detection methods, aims to select the method more suitable for the growth of aquatic microorganisms, offering new practical insights for accurately detecting the total count of heterotrophic bacteria in hospital purified water.MethodsThe most commonly used plate count agar (PCA) method, and the R2A agar culture were adopted to detect microorganisms and determine the total number of bacterial colonies in the water for oral diagnosis and treatment water and terminal rinse water for endoscopes in medical institutions. The two water samples were inoculated by pour plate and membrane filtration methods, respectively. Using statistical methods including Spearman and Pearson correlation, Wilcoxon signed-rank sum test, paired-Chi-square test, and linear regression, we analyze the differences and associations in the bacterial counts cultivated through two different methods.ResultsIn 142 specimens of the water, the median and interquartile range of the heterotrophic bacterial colony number under the R2A culture method and under the PCA culture method were 200 (Q1–Q3: 25–18,000) and 6 (Q1–Q3: 0–3700). The total number of heterotrophic bacteria colonies cultured in R2A medium for 7 days was more than that cultured in PCA medium for 2 days (P < 0.05). The linear regression results showed a relatively strong linear correlation between the number of colonies cultured by the R2A method and that cultured by the PCA method (R2 = 0.7264). The number of bacterial species detected on R2A agar medium is greater than that on PCA agar medium.ConclusionThe R2A culture method can better reflect the actual number of heterotrophic bacterial colonies in hospital purified water. After logarithmic transformation, the number of colonies cultured by the two methods showed a linear correlation.

Environmental surveillances of River Ogio in Edo State, Nigeria

AbstractThe study assessed the quality of water obtained from River Ogio in Etsako West Local Government Area of Edo State, Nigeria. Using standard procedures, the water samples obtained from three points of the river were analyzed for physicochemical parameters, Total heterotrophic bacteria count and Total coliform count. With exception of upstream samples, the temperature of midstream and downstream samples was lower than the range specified by the World Health Organization (WHO). The Cadmium and Arsenic levels, Total heterotrophic bacteria count and Total coliform count were above the WHO recommended limits. A total of four genera of bacteria were isolated from the water samples. Correlational analysis revealed no significant (p &gt; 0.05) relationship between the physicochemical parameters and bacteriological properties of water obtained from River Ogio. The water obtained from River Ogio is considered unsafe for domestic consumption due to its high heavy metal content and bacteria load.

Comparison of PetrifilmTM AC and Pour plate techniques used for the heterotrophic aerobic bacterial count in water.

Heterotrophic bacteria (HPC) are commonly found in water samples. While these bacterial counts do not necessarily indicate a health hazard, high counts provide a good indication of the efficiency of water disinfection and integrity of distribution systems. The aim of this study was to compare the PetrifimTM AC method to the Pour Plate technique for the testing of HPC in water samples. Artificially contaminated (192 samples) and natural water samples (25) were processed using two methods. Both methods accurately detected high, medium and low counts of HPC, producing average Z scores between -2 and+2. Paired-wise student t-test and correlation coefficient showed nonsignificant differences between the results of two methods. Acceptable repeatability and reproducibility was obtained using both the methods. Uncertainty of measurement for PetrifilmTM AC and Pour Plate method was found to be 2.9% and 5.4% respectively. PetrifilmTM AC proved to be robust at 33°C and 37°C. In conclusion, PetrifimTM AC, which is easy to process, read and less time consuming, proved to be comparable to the conventional Pour Plate method in establishing HPC in water. In addition, PetrifimTM AC requires less space for the processing and incubation, generate small volume of waste for disposal and requires no equipment, except for the incubator.

Microbiological Assessment and Antibiotic Susceptibility of Orogodo River Exposed to Abattoir Effluent in Delta State, Nigeria

The content of abattoir effluent and its receiving water body, Orogodo River in Agbor, Delta State. Total heterotrophic and coliform counts were assessed using standard microbiological techniques. The viable heterotrophic bacteria count for the rainy season ranges from 7.7x105-4.6x104cfu/ml. Total coliform counts 2.6x105 -3.4x104 MPN/ml respectively. A total of 11 bacteria were isolated, antibiotic susceptibility pattern of bacteria was determined using the disk diffusion method. Five out of the bacteria isolates were resistant to at least four antibiotics. Out of all the antibiotics used 90 isolates were susceptible to erythromycin, 5% were resistant, also, 85 were susceptible to ofloxacin with 5% resistance and 10% were intermediate. Ampicillin had the highest resistance of 40%. The Molecular identification of multiple antibiotic-resistant bacteria was carried out using a 16S rRNA gene sequence. The identified bacteria include Shigella flexneri, Enterobacter hormaechei, Proteus vulgarus, Morganella morganii, and Pseudomonas oryzae. Data were statistically analyzed to determine the level of significance. The microbial population of bacteria isolated was found to be higher in the abattoir wastewater sample 7.7x105 and the point of entry sites 4.0x105 when compared to the downstream and upstream sample stations. The high microbial load and presence of multiple antibiotic-resistant bacteria in the river water is alarming and can lead to public health risks when such water is consumed or used for cleaning meat during processing. There is a need for proper management of abattoir waste, An on-site pretreatment strategy (collection of waste, treatment, processing, anaerobic digestion, and safe disposal) is highly recommended and should be enforced by relevant authority to safeguard the environment and the populace that depend on the Orogodo river water.

Enhanced Phytoremediation and Physicochemical Parameters of Crude Oil Polluted Soil Using Pseudomonas fluorescens and Bacillus substilis

There have been worry over the Niger Delta's environmental contamination. Bacteria and other microorganisms have shown to be very helpful in the breakdown of hydrocarbons generated from petroleum. The goal of this research is to use elbow bufallow grass and sedge plants for phytoremediation of soil affected by crude oil. Standard microbiological techniques were applied to the contaminated soil once it was gathered. Using a hand auger, contaminated soil samples were taken twice a month for three months from two separate locations in Rivers State at two distinct depths: 0–15 cm and 15–30 cm. The following physicochemical parameters of samples were analysed using Standard Laboratory Procedures: pH, Temperature, Nitrogen, Phosphorus, Potassium available in the polluted soil and the total hydrocarbon content (THC). Two plant species common in the Ogoni region of Rivers state, i.e. Sedge plant (Schoenoplectus), Elbow buffalo grass (Panicum subalbidum) were used for phytoremediation monitoring. A combination of treatment consisting of the application of Pseudomonas fluorescens Bacillus substilis, Panicum subalbidum and Schoenoplectus senegalensis was evaluated during 28 days of remediation. Each pot contained crude oil mixture in the soil as a sole source of carbon and energy. THB counts ranged from 2.35 to 4.15 cfu/g. The statistical analysis revealed that there was no significant difference (p&gt;0.05) in the total heterotrophic bacteria counts between the samples. HUB counts range from 0.7 to 1.45cfu/g. The total bacterial population counts obtained from soil sample during bioremediation monitoring ranged from 17+1.41 (CS+PAN) to 40+1.412cfu/g (CS+PSE+BAC+PAN) in Day 1. Results of Day 14 range from 13+1.41 (CS+PAN) to 35.5+3.542cfu/g (CS+BAC+SCH). Results of Day 28 ranged from 8.5+0.71 (CS+PAN) to 27+1.412cfu/g (CS+PSE+BAC+PAN). The presence of microbial activity was determined by the enumeration and isolation of total heterotrophic and hydrocarbon utilizing bacteria. The results of physicochemical parameters before bioremediation is as follows: pH (5.43), Temperature (27oC), Electrical conductivity (9), Moisture content (7.80%), Total organic carbon (0.93%), Soil organic matter (1.60%), Nitrogen (56.695mg/kg), Phosphorus (0.621mg/kg), Potassium (7.125mg/kg) and Total Hydrocarbon content (700mg/kg). Results revealed amount of soil hydrocarbon removed and percentage (%) Bioremediation remediated after 28 days of monitoring to be higher in set up with CS+PSE+SCH (3454mg/kg; 85.28%) and lowest in set up with US+SCH (434mg/kg: 62%) and the amount of root hydrocarbon content removed and percentage (%) Bioremediation remediated after 28 days of monitoring to be higher in set up with CS+BAC+SCH (632Mg/kg; 15.6%) and lowest in set up with US+SCH (12.2mg/kg; 1.74%).&#x0D; Three (3) most occurring hydrocarbon utilizing bacterial isolates were isolated and identified culturally and phenotypically from the soil samples these bacteria isolates were confirmed to be Peudomonas, Priestia megaterium and Bacillus spp molecularly via sequencing of the 16SrRNA gene. The most common bacteria isolated were Bacillus spp at a dilution of 104. This research revealed and recommend that Panicum subalbidum as a suitable plant species for phytoremediation of crude oil-contaminated soil.

Characterization of Argentine commercial bee pollen intended for human consumption

Bee pollen is consumed as a dietary supplement. Its quality parameters are regulated by the Argentine Food Code (AFCode). The present study characterized 10 commercial dehydrated samples from five Argentine provinces to provide information on hygienic quality and health safety. We assessed their microbiological quality, including potential mycotoxins. We also determined their botanical origin and moisture. Results showed that seven out of ten samples presented lower counts of culturable heterotrophic mesophilic bacteria than those allowed by the AFCode. In contrast, all samples showed higher filamentous fungi and yeast counts than the level approved by the AFCode. No fumonisin or deoxynivalenol was detected; we observed only aflatoxin B2 in one sample and ochratoxin A in two. The results of the botanical origin of samples showed that all samples had a predominant pollen type, except one. The microbiological quality of all samples agreed with that required by the AFCode, except filamentous fungi and yeasts. In addition, we found variations among samples from the same province. Therefore, if pollen is intended for human consumption, appropriate hygiene standards must be applied to all bee pollen production operations. Highlights: The microbiological quality of bee pollen samples, regardless of the province or botanical origin, agreed with the requirements of the AFCode, except for filamentous fungus and yeast. All samples showed filamentous fungus and yeast counts higher than the permitted level in the AFCode. Mycotoxin levels found in bee pollen were far from the limits allowed in humans (10 µg.kg-1) by regulations for other foods. All samples analyzed were pollen mixes verified by identifying numerous botanical species. The characterization of Argentinian commercial bee pollen showed that it was suitable for human consumption.

Treatment of abattoir wastewater using &lt;i&gt;Moringa oleifera&lt;/i&gt; seed and snail shell in Rivers State, Nigeria

The practice of discharging abattoir wastewater into a receptacle without treatment is most likely to alter its physicochemical and microbiological properties. Against this background, this study is aimed at determining the efficacy of Moringa oleifera and snail shells as bio-coagulants for treatment of abattoir wastewater using the jar. The mean values of monitored physicochemical parameters were electrical conductivity (1227.7), total organic carbon (224.4%), biochemical oxygen demand (362.3 mg/l), chemical oxygen demand (1001.5g), total dissolved solids (462.5 mg/l), total suspended solids (1562.5) mg/l and turbidity (190.6 NTU). The mean total heterotrophic bacteria count (THBC) for untreated wastewater was 1.4 x 108 CFU/ml, total coliform count (TCC) was 5.6 x 105 CFU/ml, and total fungal count (TFC) was 1.6 x 102 CFU/ml. After treatment, the biocoagulants caused 82.5-84.2% reduction in EC, TOC (59-88.3%), BOD (90.8-93.7%), COD (94.4-95.3%), TDS (89.6-91.9%), TSS (93.3-94.5%) and turbidity (80.8-84.5%). The bio-coagulants were able to remove 92.2-95.4% of Zn, Pb (97-97.5%), Cr (97.2-98.8%) and Cd (86.7-89.3%). After treatment with the bio-coagulants, THBC dropped from 4.7 x 103-5.3 x 102 CFU/ml to 8-10 CFU/ml on day 6, TCC dropped from 4.2 x 102 – 6.7 x 10 CFU/ml to 5-7 CFU/ml on day 6 while TFC dropped from 1.1 x 102 - 1.5 x 10 CFU/ml to 2-4 CFU/ml on day 6, representing approximately 99.9% reduction in microbial load. Thus, the bio-coagulants were as good at removing pollutants in water as alum, but with the added advantages of being natural, cost-effective, and readily available.

Level of Microbial Contamination of Freshly Prepared Fufu and Retailed Fufu

Fufu is an acid-fermented products produced through submerged fermentation of cassava root in water for days. The study was set to determine the microbiological quality and the physiochemical composition of freshly prepared fufu (FF) and retailed fufu (RF). A standard microbiological method was used in enumerating and identify bacteria and fungi species isolated. The total heterotrophic bacteria count ranges from Log10 cfu/g 2.14 to 6.18 and 3.56 to 7.06 for retailed fufu and freshly prepared fufu respectively. Predominant bacteria found in the samples studied and their percentage of distribution were Lactobacillus 17(23%), Escherichia coli and Staphylococcus sp. 14(19%), Bacillus sp. 13(18%), Micrococcus sp. 5(7%), Enterobacter and Corynebacterium were 4(5%) and Proteus has the least 3(4%). Among the fungi were Mucor sp. and Candida sp. were 6(26.1%), Aspergillus niger 4(17.4%), Saccharomyces sp. 5(21.7%), and Rhizopus sp.2(8.7). The proximate analysis revealed an insignificant difference in crude protein ranging from 1.36% in FF to 1.24 in RF, carbohydrates content 82.88% to83.12% in RF and FF, ash content is higher in FF ranging 7.33% to 1.53% RF, while the moisture content is higher in RF with 9.47% and 1.78% in FF. Magnesium ranges from 38.4mg/ml in FF to 35.3mg/ml in RF .The results obtained showed that the fufu samples that were retailed were more contaminated than the freshly prepared fufu which might pose risk to health. Therefore, there is a need for proper sanitary conditions and best processing and production especially during packing is recommended.

Spring water quality monitoring using multiple bioindicators from multiple collection sites

ABSTRACT The aim of this study was to examine the water quality of the Extrema River spring in a Brazilian Cerrado area. Three collection sites (P1 − P3) were sampled in the dry and rainy seasons, which are close to industries from different sectors. In the physicochemical analysis, a decrease in dissolved oxygen levels (<5 mg/L) and pH (< 6) at P3 was detected. An increase in heterotrophic bacteria count was recorded at all sites (> 500 colonies/ml). In ecotoxicological analyses, P2 and P3 exhibited toxicity using Vibrio fischeri (> 20%). In evaluating toxicity, the reduction in seed germination was significant utilizing Lactuca sativa at all locations and with Allium cepa only at P2; rootlet length was decreased at P3 on L. sativa and at all sites with A. cepa. In contrast, loss of membrane integrity and mitochondrial function of meristems was adversely affected at all locations using both L. sativa and A. cepa assays. Principal components analysis (PCA) approach indicated that seasonality apparently did not markedly interfere with the obtained data, but it is important to include more collection locations to be evaluated with multiple bioindicators in the spring region. Our data indicate the urgent need for more rigorous programs to monitor the discharge of effluents into water springs.

Effects of dissolved organic carbon and total ammonia nitrogen concentrations with the same DOC/TAN on biofloc performance

The regulation of the carbon-to‑nitrogen ratio (C/N) is at the core of biofloc technology. This study compared the performance of bioflocs under different dissolved organic carbon (DOC) and total ammonia nitrogen (TAN) concentrations but the same DOC/TAN ratio. Dissolved organic carbon and total ammonium nitrogen were set at 200 mg/L and 10 mg/L (Group 200/10), 100 mg/L and 5 mg/L (Group 100/5), and 50 mg/L and 2.5 mg/L (Group 50/2.5), respectively. The TAN removal rates of groups A, B, and C were 1.89 ± 0.02 mg N/g TSS·h, 1.63 ± 0.03 mg N/g TSS·h, and 1.32 ± 0.02 mg N/g TSS·h, respectively, and the differences were significant (P < 0.05). At the phylum level, the microbial community structure was dominated by Proteobacteria, Bacteroidetes, Actinobacteria, Verrucomicrobia, and Planctomycetes. At the genus level, Gemmobacter, Hydrogenophaga, and Microbacterium were the dominant genera. Most of bacteria community differed significantly among the three groups. As the concentration of carbon and nitrogen sources increased, the Shannon index showed a decrease in bacterial diversity, and the number of heterotrophic bacteria significantly increased. The crude protein content of flocs in group A ((29.22 ± 0.20)%) was significantly lower than that in groups B ((30.56 ± 0.32)%) and C ((30.83 ± 0.20)%). In groups A and B with higher carbon and nitrogen concentrations, the copy numbers of genes related to nitrification were relatively low, but the copy numbers of genes related to denitrification were relatively high. Therefore, it can be concluded that with a ratio of 20 of DOC/TAN, increasing DOC and TAN concentrations led to a significant increase in TAN removal capacity, heterotrophic bacteria count, denitrification function gene copies, and crude protein content of bioflocs, and a decrease in bacterial diversity, nitrification function gene copies, and C/N of bioflocs (P < 0.05). These results suggest that the influence of DOC and TAN concentrations on bioflocs performance may be more significant than that of DOC/TAN, and should be fully considered in practical bioflocs technology systems.

Dietary Effects of Lactobacillus plantarum Combined with Galactooligosaccharide on Immunological and Biochemical Parameters, Gut Microbiota, Digestive Enzyme Activity, Body Composition, and Stress Resistance in Narrow-Clawed Crayfish, Pontastacus leptodactylus (Eschscholtz, 1823)

The effects of galactooligosaccharide (GOS) and varying levels of Lactobacillus plantarum (LP) on some physiological parameters as well as air exposure stress resistance in clawed crayfish (Pontastacus leptodactylus) were investigated. During a 97-day trial, 216 crayfish were fed with four experimental diets (in triplicates) including the control diet (without GOS and LP), GLP7 (GOS 2%+LP 107 CFU.g-1 diet), GLP8 (GOS 2%+LP 108 CFU.g-1 diet), and GLP9 (GOS 2%+LP 109 CFU.g-1 diet). At the end of the trial, 26% higher amounts of the total hemocyte count (THC) and semigranular cells (SGC) and 27% higher hyaline cells (HC) were observed in GLP7. A significant improvement in lysozyme value was observed in GLP7 and GLP8. Moreover, superoxide dismutase was significantly higher in GLP9, whereas the catalase (CAT) activity did not change in the experimental groups. Unlikely, plasma glucose levels decreased in all the GLP treatments. In terms of intestinal microbiota, autochthonous lactic acid bacteria (LAB) remarkably increased in all the GLP-supplemented groups, while total autochthonous intestinal heterotrophic bacteria counts (TVC) did not change in GLP-supplemented groups. However, 14 days after switching to the basal diet, no reduction was detected in TVC, but LAB levels decreased in GLP7 and GLP9 treatments. Dietary administration of GLP could beneficially modulate digestive enzyme activity, including protease, lipase, and amylase. Furthermore, higher lipid and gross energy were observed in GLP9. However, GLP-supplemented diets could not improve growth performance parameters. After 24 h subjecting to air exposure stress, although no mortality was detected, crayfish fed GLP-supplemented diets were healthier through enhanced THC, SGC, and HC levels in GLP7 and GLP9 and CAT activity in GLP7 and GLP8. These results proved the positive impacts of dietary supplementation with combined GOS and LP, with GLP8 and GLP9 as optimum diets, on immunochemical parameters, intestinal microbiota, digestive enzyme activity, and stress resistance in P. leptodactylus.