Total Fungi Research Articles

A call for further research on the relation between type 2 diabetes and oral candidiasis

This study aimed to evaluate the relationship between oral candidiasis with salivary features, neutrophil function, and glycemic control in type 2 diabetes (T2D). Twenty-nine individuals were included, 16 with T2D and 13 without the disease. The participants underwent clinical examination, neutrophilic function tests, fasting glycemia and glycated hemoglobin (A1c), stimulated and unstimulated saliva collection, and swab and exfoliative cytology. Salivary flow, pH, and total fungi count were evaluated on saliva, and identification of the Candida species was performed in saliva and swab samples. There was no difference in unstimulated salivary flow and pH of the stimulated and unstimulated saliva for participants with T2D and controls (P > .05). Individuals from both groups presented no candidal lesions. The salivary fungal growth in the T2D group was higher than that in controls (P < .05). Only individuals with T2D presented alterations in the neutrophilic functions (14/16; 87.5%; P < .05). There was no relationship between high A1c values and neutrophil dysfunction with the presence of Candida spp. in both saliva and mucosa (P > .05). High A1c level, reduction in neutrophil activity, salivary flow and pH, and increase in total salivary Candida spp. counts were not related to oral candidiasis in patients with T2D.

Effect of Different Sterilization Methods on the Microbial and Physicochemical Changes in Prunus mume Juice during Storage.

This study evaluated the pasteurization (P), ozone (O3), ultrasonic (US), and high-hydrostatic-pressure (HHP) sterilization approaches for processing of Prunus mume regarding browning factors and microorganisms, compared with non-sterilization (control check, CK) treatment. The microorganisms (total bacterial count and fungi and yeast count) in the juice were identified after different sterilization techniques, while the quality parameter changes (degree of browning, color measurements, total phenolic content, reducing sugar, ascorbic acid, 5-hydroxymethyl furaldehyde (5-HMF), amino acid nitrogen, total soluble solids (TSS), pH value) were investigated. The results indicate that P and HHP treatment reduced non-enzymatic browning while substantially impacting the color measurements, TSS, and pH, while the sterilization effect was remarkable, with a rate exceeding 90%. Furthermore, the Prunus mume juices treated with P and HHP sterilization were used as the objects, and the CK group was used as the control group. They were placed at 4 °C, 25 °C and 37 °C, respectively, and stored in dark for 15 d. Sampling and determination were carried out on 0, 3, 6, 9, 12, and 15 d, respectively. M-&-Y (molds and yeasts) were not detected in the late storage period, and no obvious microbial growth was observed during storage, indicating that P and HHP treatments could ensure the microbial safety of Prunus mume juice. P- and HHP- treated Prunus mume juice has better quality and low temperature storage is beneficial for maintaining the quality of Prunus mume juice. Therefore, P treatment or HHP treatment combined with low temperature storage could achieve a more ideal storage effect. Overall, this study conclusively established that P and HHP methods were suitable for sterilizing Prunus mume juice. These techniques minimally affected overall product quality while better maintaining the quality parameters than the untreated juice samples and those exposed to O3 and US treatment.

Fertilization effects on soil microbial composition and nutrient availability in integrated rice-livestock production systems

Integrated crop-livestock systems (ICLS) in paddies are an important strategy to reduce fertilizer requirements of rice (Oryza sativa). Legume crop rotations and fertilization increase soil carbon (C) and nitrogen (N) availability compared to rice monocropping. Our objectives were to evaluate the effects of fertilization, namely P and K, in no-till ICLS of continuously flooded rice and rice-soybean rotation in subtropical paddy fields on: (i) soil microbial community, (ii) labile C and N pools, (iii) microbial groups, and (iv) rice yield. Both ICLS were annual ryegrass pastures under beef cattle grazing during the winter season without tillage. Although flooded rice yield did not respond to P and K fertilization in either ICLS, P and K fertilization increased microbial biomass C and N content, and permanganate-oxidizable C (POxC) by 37%, 36%, and 42%, respectively, in both production systems, due to alleviation of nutrient limitation for microbial growth. ICLS under soybean-rice rotation had higher C availability and 22.4% higher rice yield than the rice monocropping. Positive relationships were observed between microbial biomass N and Gram-positive (G+; R2 = 0.61), Gram-negative (G-; R2 = 0.54) bacteria, and saprophytic fungi (R2 = 0.45). However, total fungi was almost 10 times lower than the PLFA of total bacteria on average of cropping systems. G+ bacteria were the only microbial group correlated with N availability under flooded rice. We conclude that P and K fertilization has a direct impact on the microbial community and biomass and consequently on the C and N availability, but does not increase rice yield under no-till ICLS. Soybean-rice rotation yields more than rice monocropping system under ICLS and soil bacteria are more sensitive than saprophytic fungi to changes in soil nutrient status during flooding period in paddy fields.

Total Fungi Counts and Metabolic Dynamics of Volatile Organic Compounds in Paddy Contaminated by Aspergillus niger During Storage Employing Gas Chromatography-Ion Mobility Spectrometry

Total Fungi Counts and Metabolic Dynamics of Volatile Organic Compounds in Paddy Contaminated by Aspergillus niger During Storage Employing Gas Chromatography-Ion Mobility Spectrometry

Phytoremediation of soils contaminated with crude and weathered oil using two rice varieties (Oryza sativa L.)

Objective: To evaluate the potential for soil phytoremediation with new and weathered hydrocarbons with two rice varieties (Oryza sativa L.). Materials and Methods: The assessed treatments were 150 mg kg-1 (control soil), 30,000; 60,000 and 90,000 mg kg-1 of new oil and 79,457 mg kg-1 of weathered oil 1 and 42,000 of mg kg-1 of weathered oil 2; they were established in a completely randomized design with 6 x 3 factorial, with four repetitions each. The evaluated variables were populations of total bacteria (colony forming units CFU per grams of dry soil), free-living nitrogen-fixing bacteria (CFU), total fungi (CFU), and total dry biomass (g). Total bacteria and fungi were quantified at the beginning of the experiment at 90 and 145 days. Results: The highest total petroleum hydrocarbons (HTP) degradation was 73 and 72 % in the 79,457 and 42,000 mg kg-1 concentrations of weathered HTP 1 and 2, in the rhizosphere of rice silver line 21. The total dry biomass reported significant differences (p ≤ 0.05), evidencing a lower effect in the 60,000 mg kg-1 concentration in new oil, which caused a 33 % reduction compared to the control. Results/Conclusions: The rice variety line 21 has a greater potential to phytoremediate soils contaminated with crude and weathered oil in field conditions in tropical areas.

Planting Systems Affect Soil Microbial Communities and Enzymes Activities Differentially under Drought and Phosphorus Addition.

The use of phosphorus (P) to alleviate soil nutrient deficiency alters resources in plant and microbial communities, but it remains unknown how mixed and monospecific planting of forest tree species shape soil microbial structure and functions in response to drought and its interplay with phosphorus addition. We investigated the microbial structure and chemical properties of forest soils planted with P. zhennan monoculture, A. cremastogyne monoculture, and their mixed cultures. The three planting systems were exposed to drought (30–35% water reduction) and the combination of drought with P. A well-watered treatment (80–85% water addition) of similar combinations was used as the control. Planting systems shaped the effects of drought on the soil microbial properties leading to an increase in nitrate nitrogen, urease activity, and microbial biomass carbon in the monocultures, but decrease in mixed cultures. In the monoculture of P. zhennan, addition of P to drought-treated soil increased enzyme activities, the concentration of dissolved organic nitrogen, and carbon, leading to increase in the total bacteria, G+ bacteria, and arbuscular mycorrhizal fungi. Except in the drought with P addition treatment, the impact of admixing on total phospholipid fatty acids (PLFAs), bacterial PLFA, and fungi PLFA was synergistic in all treatments. Our findings indicated that in monoculture of P. zhennan and its mixed planting with A. cremastogyne, greater biological activities could be established under drought conditions with the addition of P.

Changes in organic carbon and microbiology community structure due to long-term irrigated agriculture on Luvisols in the Brazilian semi-arid region

Changes in the global water cycle affect irrigation requirements and soil processes as well as the structure of soil microbial communities and function and the carbon (C) balance. The microbial structure and C sequestration under land use changing scenarios are rarely studied in the semi-arid region of Brazil. Here, we assessed the effects of land-use changes (irrigation and cultivation) on C storage in the soil and the structure of total bacteria (16S rRNA gene profile) and fungus (18S rRNA gene profile) at soil depth. We evaluated two soil profiles in the semi-arid region in northeastern Brazil. Profile P1 in an area with long-term irrigation (1,500 mm of water per year) and cultivation (small-scale farming systems, mainly with subsistence crops, which is a frequent land use system in the region of irrigated soil) for about 26 years. Profile P2 under natural conditions with 400 mm of water per year of rainfall (rain-fed hyperxerophilic Caatinga). Land-use changes showed a small influence on C storage; however, the changes strongly affected the soil organic matter (SOM) quality as well as the bacterial and fungal community structure, indicated by higher contents of labile-C and microbial biomass along with lower C-CO2 emission. The relatively large amounts of aliphatic groups in the soil surface and subsurface in the cropped system (P1) suggested enrichment of methylene structures and probable increase of microbial-derived compounds. Methoxylic and aromatic groups tend to increase at depth (Bt horizon) indicating that the subsoil C responds to soil management changes. The structures of the bacterial community are distinct at depth in P1 and more similar at depth in P2. On the other hand, the structures of the fungal communities are more similar at depth in P1 than in P2. Furthermore, the irrigated agriculture also presented a carbon management index greater than 140% in most horizons, indicating that the soil management system did not cause soil degradation.

Evaluation of the Microbial Population of Soil around Oilfield Wastewater Pond

The microbial quality of soil around the oilfield wastewater discharge pond was investigated to determine the microbial dynamics in the soil. Soil samples were randomly collected at four different parts around the pond and 80 meters away from the pond (control) at a depth of 0-15cm with a clean auger into sterile polythene bags from Ogbogu flow Station. The total heterotrophic bacteria, total heterotrophic fungi, hydrocarbon utilizing bacteria, and fungi were determined using standard microbiological methods. The bacterial isolates were identified using standard biochemical tests while fungal isolates were identified based on appearance on plates and microscopy. The mean counts for the total heterotrophic bacteria, fungi, hydrocarbon utilizing bacteria and fungi in the rainy season for the soil within the pond was 2.10×107, 4.63×104, 1.38×104, and 2.93×104 CFU/g, respectively. The mean counts for the total heterotrophic bacteria, fungi, hydrocarbon utilizing bacteria and fungi in the dry season for the soil within the pond was 5.72×106, 1.87×104, 2.80×103, and 1.37×103 CFU/g, respectively. The mean counts for the total heterotrophic bacteria, fungi, hydrocarbon utilizing bacteria and fungi in the rainy season for soil 80 m away from the pond was 2.50×107, 1.07×105, 2.4×103, and 1.9×103 CFU/g, respectively. The mean counts for the total heterotrophic bacteria, fungi, hydrocarbon utilizing bacteria and fungi in the dry season for soil 80 m away from the pond was 6.17×106, 2.0×104, 1.83×103, and 1.23×103 CFU/g, respectively. Statistical analysis showed a significant difference (P≤0.05) in the total heterotrophic bacterial count from the pond and that of soil around 80 m away from the pond. The heterotrophic counts during the dry season were significantly lower (P≤0.05) from that of the rainy season in all the samples analyzed. There was a significant difference (P≤0.05) between the fungi count of soil 80 m away in the dry season from that of soil around the pond. There was no significant difference (P≥0.05) in the total fungal counts recorded for the dry and rainy season in the various samples except that of the soil 80 m away. Hydrocarbon utilizing fungi was higher in the soil around the pond and was significantly different (P≤0.05) from that of soil 80 m away from the pond during the dry season. Bacillus spp., Aeromonas spp., Micrococcus spp., Staphylococcus spp., Chryseomonas spp., Proteus spp., Pseudomonas spp., Klebsiella spp., Actinomyces spp., Enterobacter spp., Rhodococcus spp., and E. coli were identified from the soil. While Bacillus spp, Micrococcus spp, Staphylococcus spp, Proteus spp, and Pseudomonas spp were the hydrocarbon utilizing bacteria. Eight fungal genera isolated from the samples include Aspergillus fumigatus, Aspergillus niger, Aspergillus flavus, Saccharomyces cerevisiae, Geotricum, Trichoderma, Fusarium, and Penicillium spp. Hydrocarbon utilizing fungi isolated includes Aspergillus niger, Aspergillus flavus, Fusarium spp., Penicillium spp., and Saccharomyces cerevisiae. This investigation revealed high microbial population in the soil 80m away from the pond than those within the soil around the wastewater pond. The microbial population was affected by the season with the rainy season having a higher microbial population than the dry season.

Ammonia-oxidizing bacteria and fungal denitrifier diversity are associated with N2O production in tropical soils

Nitrous oxide (N2O) production in tropical soils cultivated with sugarcane is associated with ammonia-oxidizing bacteria (AOB) and fungal denitrifiers. However, the taxonomic identities and the community diversities, compositions, and structures of AOB and fungal denitrifiers in these soils are not known. Here, we examined the effects of applying different concentrations of an organic recycled residue (vinasse: regular non-concentrated or 5.8-fold concentrated) on the dynamics of AOB and fungal denitrifier community diversity and composition and greenhouse gas emissions during the sugarcane cycle in two different seasons, rainy and dry. DNA was extracted from soil samples collected at six timepoints to determine the dynamics of amoA-AOB and nirK-fungal community diversity and composition by amplicon sequencing with gene-specific primers. Bacterial and archaeal amoA, fungal and bacterial nirK, bacterial nirS and nosZ, total bacteria (16S rRNA) and total fungi (18S rRNA) were quantified by real-time PCR, and N2O and CO2 emissions were measured. The genes amoA-AOB and bacterial nirK clade II correlated with N2O emissions, followed by fungal nirK. The application of inorganic nitrogen fertilizer combined with organic residue, regardless of concentration, did not affect the diversity and structure of the AOB and fungal denitrifier communities but increased their abundances and N2O emissions. Nitrosospira sp. was the dominant AOB, while unclassified fungi were the dominant fungal denitrifiers. Furthermore, the community structures of AOB and fungal denitrifiers were affected by season, with dominance of uncultured Nitrosospira and unclassified fungi in the rainy season and the genera Nitrosospira and Chaetomium in the dry season. Nitrosospira, Chaetomium, Talaromyces purpureogenus, and Fusarium seemed to be the main genera governing N2O production in the studied tropical soils. These results highlight the importance of deciphering the main players in N2O production and demonstrate the impact of fertilization on soil microbial N functions.

Tillage and residue management affect growing-season soil respiration in paddy fields

Farmland soil respiration (SR) plays a pivotal role in affecting global carbon (C) cycling. To examine impacts of paddy management (including tillage and residue management) on growing-season SR, four long-term treatments were established: conventional tillage with residue mulching (CTM), conventional tillage with residue removal (CT), reduced tillage with residue mulching (RTM), and reduced tillage with residue removal (RT). All treatments lasted for six years starting on October 19th, 2014. Since the growing season is May to October, the measurements were performed from May 8th to September 30th, 2020. In-situ measurements were made of SR, and corresponding soil samples were collected and analyzed for soil texture, soil nutrient, soil organic carbon (SOC), C composition, and soil microbial abundance. Results showed that four treatments had a significant difference in terms of growing-season SR. The cumulative SRs of CT, CTM, RT, and RTM were 2.066, 2.502, 2.396, and 2.649 kg m-2, respectively. The observation was contrary to the conventional perspective that no-tillage with residue mulching leads to lower CO2 emissions. For soil microbial abundance, compared with CTM, RT, and RTM, CT had the lowest contents of total PLFA, bacteria, and fungi. In addition, CT had the lowest unstable C compositions, and the highest stable C compositions among all treatments. Redundancy analyses (RDA) indicated that cumulative SR increased with the increase of soil microbial abundance. Further, Pearson correlation analyses showed that cumulative SR had a positive correlation with unstable C characteristics and a negative correlation with stable C characteristics. The results suggested that CT is more conducive than the other three treatments in slowing the growing-season SR. This study provides novel insights regarding the impact of agricultural management on growing-season SR, which has practical significance for the management of agricultural lands in the context of carbon cycling.

Kuantitas Mikrob Tanah pada Lahan Jagung dengan Aplikasi Ekstrak Alga

Organic fertilizers contain complete nutrients needed by plants, such as humic acid and fulvic acid, that can promote plant growth and increase the population of beneficial microbes in the soil. Algae can be an organic fertilizer in extract preparations that can increase plant growth and improve soil composition. The calculated number of microbes from the soil on corn land with the application of algae extracts affects the population of soil microbes both by standard plate count (SPC) and most probable number (MPN) methods. The total number of bacteria by SPC in the control soil was 3.1 × 105 CFU/g, while the total fungus was only 1.7 × 104 CFU/g upon applying 5% algae extract. The most microalgae by MPN in the control ground was estimated to be 2.6 × 104 cells/g. Therefore, the application of algae extract affects the number of soil microbes on corn land compared to control soil. The algae extract reduces the number of bacteria and algae but increases the number of fungi on cornfields.&#x0D; &#x0D; Keywords: algae extracts, cornfields, soil microbes

Scanning electron microscope energy dispersive X-Ray, chemical, organoleptic, and microbiological quality of banana peel (Musa paradisiaca L.) at different fermentation durations.

This research aims to examine the effect of different fermentation times on the results of scanning electron microscope energy dispersive X-ray (SEM-EDX), chemical, organoleptic, and microbiological quality of banana peel. The design in this study used a completely randomized design (four treatments and four replications). The treatments in this study were different durations of fermentation of banana peels; T0 = no fermentation; T1 = 6 days; T2 = 12 days; and T3 = 18 days. The research parameters were chemical, organoleptic, microbiological quality, composition, and SEM-EDX images. Analysis of chemical, organoleptic, and microbiological quality data was done using analysis of variance, followed by Duncan's multiple range testing at the 5% significance level, while the elemental composition and SEM-EDX images were analyzed descriptively. The results of the study showed that the length of fermentation had a significant effect (p < 0.05) on moisture content, ash, crude fiber, nitrogen-free extract, and all organoleptic quality variables of banana peels. Different fermentation durations had no effect (p > 0.05) on crude protein, ether extract, metabolic energy, total lactic acid bacteria, total bacteria, Gram positive or negative bacteria, and total fungi on banana peels. The analysis showed that the elemental composition of banana peels is C, Na2O, Cl, K2O, MgO, SO3, SiO2, and P2O5. Eighteen days of fermentation improved the chemical quality, organoleptic, microbiological, elemental composition, and SEM-EDX image of fermented banana peel.

Soil health within transitions from irrigation to limited irrigation and dryland management

AbstractThe decline in groundwater supply in the Texas High Plains is forcing some growers to convert center‐pivot irrigated cropland to dryland production. Transitioning toward reduced water input can lead to declines in soil health. We assessed short‐term changes in soil health indicators in two transition scenarios: (a) from high irrigation method to low irrigation method (center pivot to subsurface drip) and (b) from high irrigation method to dryland (center pivot to dryland), in comparison to continuous center‐pivot management. We monitored changes in chemical and biological indicators in four fields for each transition scenario and in three pivot‐irrigated fields. There were declines in soil water content, potassium (K), sodium (Na), and soil organic carbon with transition from irrigation to reduced irrigation and dryland. Severe drought in the final year revealed reduced amounts of multi‐enzyme activities, total ester‐linked fatty acid methyl ester (EL‐FAME), and total fungi. Transitioning to low water‐input management in this environment complicates efforts to maintain microbial components of soil health. Longer‐term comparisons are needed to detect slow changes in soil health indicators on producers’ fields.

Immunological and bacteriological quality of fresh cow colostrum and passive immunity transfer in selected dairy farms in Fars, Iran.

The quality of colostrum is affected by IgG level and microbial load. The quality of colostrum used in feeding dairy calves and passive immunity transfer in selected dairy farms in Fars province, Iran was investigated. A total of 75 colostrum and neonatal blood samples were collected from 11 herds. The immunological quality of colostrum was assessed using a Brix digital refractometer. The bacteriological quality was assessed by performing total plate count (TPC), total coliform count (TCC), spore-former count, fungi count, and species-specific PCR assay to detect some bacterial species. The mean Brix of colostrum samples was 25.4% and 72% of the samples had a Brix score ≥22%. The mean serum Brix and the prevalence of failure of passive transfer (FPT) were 10% and 4%, respectively. The mean TPC, TCC, spore-former count, and fungi count were 3.6 × 105, 2.8 × 104, 3.2 × 104, and 1.1 × 104 CFU/ml, respectively. The results showed that 50, 5.9, and 4% of colostrum samples were positive for Staphylococcus spp., Salmonella spp. and Maycobacterium paratuberculosis, respectively. There was no evidence of contamination with Brucella spp., Corynebacterium bovis and Mycoplasma bovis. Considering all colostrum quality indicators comprehensively, only 37.3% of the studied samples met the industry standard. A large number of calves were at risk of receiving poor quality colostrum, especially in terms of microbial contamination. Further researches are needed to evaluate the colostrum management and the effect of bacterial contamination of colostrum on the health of neonate calves in this region.

Bacteriological assessment of a salted pork product (Unaminung) sold in Calabar metropolis

The study was carried out to evaluate the microbiological quality of Unaminungsold at watt market in Calabar,Nigeria.Samples of Commercial Ui (CUi) from three processors (P1, P2, P3) were assessed for Total Bacteria Count (TBC, log cfu/g) and Total Fungi Count (TFC, log cfu/g)using standard procedures.The bacteria and Fungi isolates were also characterized and identified.The TBC of 3.36 ±0.02 (P2) was higher than 3.17±0.20 (P3) and 3.07±0.11(P1).The bacteria isolated were identified asBacillus spharius, Staphylococcus epidermidis, Staphylococcus aureus, Streptococcus avium, Aerococcusviridans. while the fungi isolatewere Verticilliumalbo-atrum, Rhyzopusstolonifera, Penniciliumcitrinum, Candida pseudotropicalis, Candida tropicalis, Saccharomyces estuary.The results revealed that the hygienic condition of the meat was within acceptable standard for human consumption. There is need for the processors to be educated on proper handling and personal hygiene to avoid cross contamination during processing.

Microbial Assessment of Kunu Sold in Awka Metropolis

Kunu is a non-alcoholic Nigerian beverage produced locally from cereals and has been widely accepted as a nutritional drink. The need for evaluation of its nutritional and safety status is very much essential. This work was carried out to determine the microbiological quality of “kunu-zaki” beverages sold in Awka metropolis. Three samples of “kunu-zaki” beverages were obtained from three different locations in Awka, Anambra state namely; Amansea, Eke-Akwa and Amawbia, labelled P, Q and R, respectively. These samples were tested for both bacterial and fungal contamination. The results show that for the colony counts from the Kunu samples ranged from 0.5×105 to 3.2 ×105 for total coliform bacteria, 2.5×105 to 4.2×105 for total heterotrophic fungi for the three samples analyzed. Bacterial isolates identification revealed the presence of Bacillus sp, Pseudomonas sp., Escherichia coli and Streptococcus sp, while the fungal isolates include; Aspergillus sp., Penicillium sp, Fusarium sp and Saccharomyces sp. The data revealed that all the Kunu drinks sold within the study area were contaminated and also contained different pathogenic microorganisms which can serve as sources of infections to human. Therefore, proper hygienic and sanitary measures need to be enforced during production, processing and packaging of this local beverage drink.

Isolation of Heterotrophic and Hydrocarbon-Utilizing Fungi from Selected Mechanic Workshops in Port Harcourt

Spent engine oil wastes in soils are currently considered one of the most serious environmental problems. This type of pollution decreases or fully destroys soil fertility, changes the elemental composition of soil. After their introduction into soil, hydrocarbons affect soil microorganisms directly or indirectly. In this study the population of heterotrophic and hydrocarbon utilizing fungi was investigated in soils from different mechanic workshop in Port Harcourt, Rivers State. Soil physicochemical parameters such as pH, temperature, nitrate, phosphorous, potassium, total hydrocarbon content and heavy metals like Pb and Cd were also determined. Standard procedures were followed in the mycological and physicochemical parameters determination. In the soil samples, counts of the total heterotrophic fungi ranged from 0.87±3.62 to 6.9±3.37 ×104 cfu/g soil while counts of the hydrocarbon utilizing fungi ranged from 0.85 ±1.91 to 2.75±1.26 ×103 cfu/g soil. The control soil sample recorded more total heterotrophic fungal counts with significant difference while the soil from the mechanic workshops recorded more hydrocarbon utilizing fungal counts than the control soil sample and was significantly different. Eight fungal genera were isolated and they include Mucor, Aspergillus, Penicillium, Blastomyces, Scedosporium, Microsporium, Candida and Scopulariopsis. Fungal genera such as Microsporium, Candida and Scopulariopsis were not isolated from soils from the mechanic workshops but only isolated from the control soil sample. The pH values ranged between 5.81 to 7.91, temperature ranged from 27.7 to 30 oC, nitrate value ranged from 0.04 to 0.21 mg/kg, PO4 ranged from 1.10 to 3.42 mg/kg, total hydrocarbon content (THC) value ranged from 0 to 170.01 mg/kg, potassium (K) value ranged from 5.063 to 17.013 mg/kg. The heavy metals analyzed were Pb (Lead) and Cd (Cadmium). The Pb ranged from 0.10 to 5.12463 mg/kg, cadmium ranged from 0.13 to 1.65072 mg/kg. The soil samples from mechanic workshops were contaminated with hydrocarbons, and the fungal isolates were primarily hydrocarbon utilizers that may be exploited for contaminated soil bioremediation.

Microbiological Characteristics and Heavy Metal Pollution of Crude Oil Contaminated Water Bodies in Port Harcourt Metropolis, Nigeria

Crude oil exploration has been beneficial to our economy but detrimental to our environment with the artisanal refineries further compounding the challenge. This research was aimed at investigating the microbiology and heavy metal pollution of three crude oil polluted rivers in Rivers State, Nigeria and effects on living organisms inhabiting that environment. This study was carried out in three locations in South-South Nigeria (Eagle Island, Iwofe and Chokocho rivers). A total of 64 water samples (upstream and downstream points) were collected using appropriate containers and sterile polyethene bags for 6 crab samples for a period of three months. Water and crab samples were analyzed for heavy metals using Atomic Absorption Spectrophotometric method while microbiological analysis involved isolation and enumeration of microbial populations of the water and crab samples as well as characterization and identification of the isolates using standard methods Results showed Total Heterotrophic bacteria (THB) ranged from 6.0 × 106 cfu/ml to 9.0 × 108cfu/ml for the downstream locations and 1.7 × 106cfu/ml to 3.5 × 107cfu/ml for the upstream locations. Total Heterotrophic Fungi (THF) ranged from 2.0 × 104cfu/ml to 1.1 × 105cfu/ml for downstream locations and 0.1 × 104cfu/ml to 4.0 × 104cfu/ml for upstream locations, Hydrocarbon Utilizing Bacteria (HUB) ranged from 0.8 × 103cfu/ml to 4.0 × 103cfu/ml in downstream locations and 2.0 × 103cfu/ml to 7.4 × 103cfu/ml in upstream locations, Hydrocarbon Utilizing Fungi (HUF) ranged from 1.0 × 103cfu/ml to 6.0 × 103cfu/ml for downstream locations and 5.0 × 102cfu/ml to 8.0 × 103cfu/ml for upstream locations. The bacteria identified biochemically included Serratia sp., Enterobacter sp. and Salmonella sp. for the crab samples and Bacillus sp. was dominant in the water samples (Bacillus subtilis, Bacillus cereus, Bacillus carboniphilus). The heavy metals (Fe, Ni, Zn, Cd, Cu, Mn, Cr and Pb) were below the DPR permissible limit but are likely to increase since the activities leading to pollution are still ongoing. The crab as a filter feeder, had higher concentration of heavy metals and microbial population and the location with the highest crude oil pollution (14.5mg/l) had the lowest THB (6.0 × 106cfu/ml) as physicochemical parameters like the amount of Dissolved Oxygen had been altered.

Airborne bacterial and fungal concentrations and fungal diversity in bedrooms of infant twins under 1 year of age living in Porto

Exposure to airborne microorganisms has been linked to the development of health detriments, particularly in children. Microbial pollution can constitute a relevant health concern indoors, where levels of airborne microorganisms may be specially increased. This work aimed to characterize the airborne bacterial levels, and fungal concentration and diversity to which twins are exposed in their bedrooms (n = 30) during the first year of life. Bacterial and fungal levels varied widely across the studied bedrooms, with 10% of the rooms presenting values exceeding the national limit for both indoor bacterial and fungal counts. Cladosporium was the predominant genera, but Penicillium, Aspergillus, Alternaria, Trichoderma and Chrysonilia were also identified in the samples collected. In addition, two toxicogenic species, A. flavus and T. viride, were identified at counts that exceeded the established limit (12 CFU/m3) in 3 and 7% of the bedrooms surveyed, respectively. Based on indoor-to-outdoor concentration ratios, outdoor air seemed to be the main contributor to the total load of fungi found indoors, while airborne bacteria appeared to be mainly linked to indoor sources. Higher indoor nitrogen dioxide levels were negatively correlated with indoor fungi concentrations, whereas particulate matter and volatile organic compounds concentrations were associated with an increase in fungal prevalence. In addition, rooms with small carpets or located near outdoor agriculture sources presented significantly greater total fungal concentrations. Multiple linear regression models showed that outdoor levels were the single significant predictor identified, explaining 38.6 and 53.6% of the Cladosporium sp. and total fungi counts, respectively. The results also suggest the existence of additional factors contributing to airborne biologicals load in infants’ bedrooms that deserve further investigation. Findings stress the need for investigating the existence of declared interactive effects between chemical and biological air pollutants to accurately understand the health risk that the assessed levels can represent to infants.

Biochar reduced soil nitrous oxide emissions through suppressing fungal denitrification and affecting fungal community assembly in a subtropical tea plantation

Biochar amendment has been shown to reduce nitrous oxide (N2O) emissions from acidic soils in tea plantations. Given that both soil bacterial and fungal denitrifications can produce N2O, their relative contributions to the decrease in N2O emissions following biochar amendment remain unclear. Here, we examined soils sampled from a subtropical tea plantation that had received 2 years of biochar amendment. Measurements of the relative contributions of fungi and bacteria to N2O production were taken by the substrate-induced respiration method implemented with the addition of selective inhibitors. The abundances of total fungi, bacteria, and key N2O-related bacterial genes were quantified by q-PCR, and the composition of the fungal community was analyzed by 18S rRNA amplicon sequencing. The results showed that the contribution of fungi to N2O production (52%) was greater than that of bacteria (18%) for the N-applied acidic soils. Biochar amendment significantly decreased the fungal abundances and the fungal contribution to N2O production (by 28%). In contrast, biochar amendment significantly increased the abundances of N2O-related bacteria (e.g., ammonia-oxidizing bacteria (AOB), nirS, nosZ). Structural equation models (SEMs) revealed that biochar decreased the fungal contribution to N2O production through enhancing the soil pH and shifting the fungal community composition. Our results highlight that the decreased N2O emissions could be ascribed to the stimulated N2O consumption process (driven by N2O-consuming bacteria encoded by the nosZ gene) and suppressed fungal dominance in acidic soils from tea plantations. This study presents relatively comprehensive insights into the regulatory roles of biochar on soil microbe-mediated N2O production processes.