Enhanced Oxytetracycline Production by Streptomyces rimosus in Submerged Co-Cultures with Streptomyces noursei

In the present study, Streptomyces rimosus was confronted with Streptomyces noursei, Penicillium rubens, Aspergillus niger, Chaetomium globosum, or Mucor racemosus in two-species submerged co-cultures in shake flasks with the goal of evaluating the oxytetracycline production and morphological development. The co-culture of S. rimosus with S. noursei exhibited stimulation in oxytetracycline biosynthesis compared with the S. rimosus monoculture, whereas the presence of M. racemosus resulted in a delay in antibiotic production. Different strategies of initiating the “S. rimosus + S. noursei” co-cultures were tested. The improvement in terms of oxytetracycline titers was recorded in the cases where S. noursei was co-inoculated with S. rimosus in the form of spores. As the observed morphological changes were not unique to the co-culture involving S. noursei, there was no evidence that the improvement of oxytetracycline levels could be attributed mainly to morphology-related characteristics.

Myco-enhanced Bioremediation in Open Field Crude Oil Contaminated Soil Using Mucor racemosus and Aspergillus niger

Aim: To assess the Mycoremediation potential of Mucor racemosus and Aspergillus niger in open field crude oil contaminated soils in Rivers State, Nigeria. Study Design: The study employs experimental design, statistical analysis of the data and interpretation. Place and Duration of Study: Rivers State University demonstration farmland in Nkpolu-Oroworukwo, Mile 3 Diobu area of Port Harcourt, was used for this study. The piece of land is situated at Longitude 4°48’18.50” N and Latitude 6ᵒ58’39.12” E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 square meter. Mycoremediation process monitoring lasted for 56 days, analyses were carried out weekly at 7 days’ interval. Methodology: Five (5) experimental plots were employed using a Randomized Block Design each having dimensions of 100 x 50 x 30 cm (Length x Breadth x Height) and were formed and mapped out on agricultural soil, each plot was contaminated with 22122.25g of Crude Oil except Control 1 and left fallow for 6 days after contamination for proper contamination and exposure to natural environmental factors to mimic crude oil spill site. On the seventh day bio-augmentation process commenced using two (2) fungal isolates namely Aspergillus niger [Asp] and Mucor rasemosus [Muc]). Two (2) control plots (P1: Uncontaminated and unamended soil - CTRL 1 US) and P2: Crude Oil contaminated but unamended soil - CTRL 2 CS); P3 = P5 were contaminated and amended/bioaugmented (P3: CS+Asp, P4: CS+Muc, P5: CS+Asp+Muc respectively. Soil profile before and after contamination was assayed while parameters like Temperature, pH, Nitrogen, Phosphorus, Potassium and Total Petroleum Hydrocarbon (TPH) contents were monitored throughout the experimental period. Microbial analyses such as Total Heterotrophic Bacteria (THB), Total Heterotrophic Fungi (THF), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF) were recorded. Bioremediation efficiency was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to the residual hydrocarbon at day 56 of bio- augmentation/ biostimulation plots with the control. Results: Results revealed actual amount of remediated hydrocarbon and % Bioremediation Efficiency at 56 days in the different treatment plots (initial TPH contamination value of 8729.00mg/kg) in a decreasing order as follows: CS+Muc (8599.19mg/kg; 33.66%) > CS+Asp+Muc (8357.31mg/kg; 33.04%) > CS+Asp (8341.58mg/kg; 32.98%) > CTRL 2 -CS (Polluted soil without amendment) (81.06mg/kg; 0.32%). Microbiological results After fifty-six (56) days of bioremediation monitoring; %HUB were as follows; CS+Asp+Muc (45.30%) > CS+Asp (40.32%) > CS+Muc (35.01%) > CTRL 2 –CS (30.43%) > CTRL 1 – US (0%). These results indicate that the presence of the contaminated crude oil stimulated and sustained the growth of Hydrocarbon Utilizing Bacteria (HUB) in the contaminated plots (P2 - P3); more so, the higher growth in the enhanced bio-augmented plots (P3 – P5) shows the positive impact of fungal bio-augmentation in bioremediation of crude oil polluted soil. It was further observed that treatment plots with higher HUB or HUF had higher percentage (%) bioremediation efficiency; that is, the higher the sustained HUB and HUF population, the higher the %Bioremediation process. Hydrocarbon Utilizing Bacteria (Log10 CFU/g): CS+Asp (4.20) (Day 35) > CS+Muc+Asp (4.18) (Day 35) > CS+Muc (4.08) (Day 28) > CTRL 2 – CS (3.95) (Day 21) > CTRL 1 – US (3.78) (Day 35). (Fig. 3). Hydrocarbon Utilizing Fungi (Log10 CFU/g): CS+Asp (4.68) (Day 35) > CS+Muc+Asp (4.58) (Day 35) > CS+Muc (4.48) (Day 35) > CTRL 2 – CS (4.23) (Day 21) > CTRL 1 – US (2.85) (Day 42). Conclusion: Study showed that bioremediation of crude oil-contaminated soils with Bioaugmenting fungus singly may be more effective than combination with others depending on the type of substrate used, nature of the hydrocarbon utilizing organism and environmental conditions prevalent as seen in Mucor racemosus having higher bioremediation potential than when combined with Aspergillus niger. Notably, Hydrocarbon Utlilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF) which are the key players in Bioremediation has its peak count value on Day 35, this confers that nutrient renewal on bioremediation site should be at interval of 35 days for continuous effective bioremediation of hydrocarbon pollutants. It is therefore recommended that single microbes of high bioremediation potential could be used since its more effective than consortium of many hydrocarbon utilizing microbes. Also, nutrient or bio-augmenting microbes’ renewal on bioremediation site should be at an interval of 35 days for continuous effective bioremediation of hydrocarbon pollutants.

Percentage Bioremediation Assessment of Spent Mushroom Substrate (SMS) and Mucor racemosus in Hydrocarbon Contaminated Soil

Aim: The aim of the study was to assess Percentage Bioremediation of Spent Mushroom Substrate (SMS) and Mucor racemosus in hydrocarbon contaminated soil Place and Duration of Study: A portion of Rivers State University demonstration farmland in Nkpolu-Oroworukwo, Mile 3 Diobu area of Port Harcourt, Rivers State was used for this study. The piece of land is situated at Longitude 4°48’18.50’’N and Latitude 6o58’39.12’’E measuring 5.4864 m x 5.1816 m with a total area of 28.4283 m2. Bioremediation monitoring lasted for 56 days, analysis carried out weekly (per 7 days’ interval). Methodology: Five (5) experimental plots employing the Randomized Block Design were used each having dimensions of 100 x 50 x 30 cm (Length x Breadth x Height) = 150,000cm3. Baseline study of the uncontaminated and the deliberately contaminated agricultural soil was investigated for its microbiota and physico-chemical properties. Two of these plots were designated as pristine (Unpolluted soil) (CTRL 1) and crude oil contaminated soil without nutrient organics and bioaugmenting microbes (CTRL 2); these two serve as controls. Each of the experimental plots, except the control (CTRL 1), was contaminated with 2500 cm3 (2122.25 g) of crude oil giving initial Total Petroleum Hydrocarbon (TPH) value of 8729.00 mg/kg. The crude oil polluted soil in Plot 3 was further treated with 750 ml of Mucor racemosus broth (CS+Muc), Plot 4 was treated with 3000 g of Spent Mushroom Substrate (CS+SMS) while plot 5 was treated with the combination of both (CS+Muc+SMS). The plots were left for 7 days to ensure even distribution and soil-oil bonding. Sampling was done at seven-day interval (Day 1, 7, 14, 21, 28, 35, 42, 49, 56). Physicochemical parameters monitored were pH, Temperature, Nitrogen, Phosphorus, Potassium, and Total Petroleum Hydrocarbon (TPH) throughout the experimental period. Microbial parameters monitored were Total Heterotrophic Bacteria (THB), Total Heterotrophic Fungi (THF), Hydrocarbon Utilizing Bacteria (HUB) and Hydrocarbon Utilizing Fungi (HUF). Percentage (%) Bioremediation was estimated from percentage (%) reduction of Total Petroleum Hydrocarbon (TPH) from day 1 to day 56 in relation to control plots. Net % Bioremediation were also assessed to ascertain the actual potential of treatment agents singly or combined. Results: Total Heterotrophic Bacteria (THB) (CFU/g) recorded on day 7 and day 56 of the bioremediation were; day 7; CTRL 1 – US (1.07 x109), CTRL- CS (5.4 x108), CS+Muc (3.0 x108), CS+SMS (4.6 x108) and CS+Muc+SMS (5.0 x108). On day 56, data obtained were CTRL 1 –US (9.4 x108), CTRL 2 –CS (7.2 x109), CS+Muc (3.7 x108), CS+SMS (8.1x108) and CS+Muc+SMS (6.8 x108). The increase in number in the treated plots is a depiction of an increase in activity of the organism and the stimulating effect of bio-organics SMS while the untreated plot CTRL 1-US showed decrease in population at day 56. Similar trend showed for Total Heterotrophic Fungi. Generally, it was observed that the highest growth/ count was recorded at the 7th and 8th week (day 42 or day 49), at the 9th week there was an observable decrease; probably due to depletion of nutrients and other factors such as rainfall and seepage. The Net Percentage Hydrocarbon Utilizing Bacteria and Fungi (Net %HUB and Net %HUF) were highest in Crude Oil contaminated plot treated with Spent Mushroom Substrate (SMS) singly; that is (CS+SMS) (11.02% and 12.07%) and lowest in the uncontaminated soil – Control (CTRL 1 –US) (5.41% and 9.26%) respectively. The trend in decreasing order of Net % Hydrocarbon Utilizing Bacteria were as follows: CS+SMS (11.02%) > CS+Muc+SMS (10.14%) > CS+Muc (9.43%) > CTRL 2 –CS (8.1%) > CTRL 1 –US (5.41%) while Net % Hydrocarbon Utilizing Fungi followed similar trend and were: CS+SMS (12.07%) > CS+Muc+SMS (11.76%) = CS+Muc (11.76%) > CTRL 2 –CS (11.05%) > CTRL 1 –US (9.26%). Evaluation of Amount of Crude Oil or Hydrocarbon remediated and Net %Bioremediation revealed Crude Oil contaminated plot augmented with Mucor racemosus broth singly (CS+Muc) as having the highest bioremediation potential while the least is the untreated soil. The trend is as follows: CS+Muc (8599.19 mg/kg; 33.93%) > CS+Muc+SMS (8298.95 mg/kg; 32.74%) > CS+SMS (8197.03 mg/kg; 32.34%) > CTRL 2 –CS (166.54 mg/kg; 0.66%) > CTRL 1 –US (85.48 mg/kg; 0.34%) Conclusion: This shows that a single nutrient substrate or augmenting microorganism applied appropriately may have a more positive result, that is; higher bioremediation potential than combined or multiple mixed treatments. It was further observed that microbial counts decreased with time in treatments with augmenting organisms alone but increased considerably in treatments supplement with organics having its peak on the 49th day. It is therefore recommended that bioremediation of crude oil-polluted soil using bio-augmenting microorganism should be applied appropriately noting the volume: area ratio and be supplemented with efficient nutrient organics after every 49-day interval.

MICROBIOLOGICAL SURVEY AND DISSEMINATION OF FILAMENTOUS FUNGI OF PUBLIC HEALTH SIGNIFICANCE FROM WATER RESERVOIR (STORAGE TANK) IN CROWN ESTATE, IGBINEDION UNIVERSITY, OKADA, NIGERIA

Results of this investigation revealed that several species of filamentous fungi are present in the reservoir waters. Samples were collected from the surface and walls of the inner storage tank. The isolation process was done by a range of techniques and media, monitored by trained taxonomist to achieve broad arrays of water-borne fungi classified to species level. The direct plate enrichment counts and filtration technique recorded the highest number of counts (59 % and 32 %) respectively. The sabauraud dextrose Agar (SDA) was observed as the medium that recorded the highest colonies (60 cfu/100 ml) for incubation period of 5 d at 30 oC. Six different fungal taxa were recovered from the three examined sites (ST1, ST2 and ST3) and the ST3 was reported to have the highest number of isolated species. However, certain fungi were observed to be more distributed than others, specifically in species of Aspergillus and Penicillium which tended to be the most common. Although, species of other genera such as Acremonium sp., Rhizopus stolonifer, Mucor racemosus and Trichophyton sp. were also present but in low counts. The significance of fungi in water systems is lowly expressed as many of the species isolated from water sources are confirmed to possess the potentiality of secreting toxic secondary metabolites like patulin, produced by P. espansum causing immune-suppression in hosts, A.flavus secrets aflatoxins that can be carcinogenic, A. versicolour releases the musty odours in homes, while some moulds are concerned in food deterioration.

Structures of the Skin Microbiome and Mycobiome Depending on Skin Sensitivity

Sensitive skin (SS) syndrome is a globally widespread, self-diagnosed discomfort characterized by subjective complaints. Although the skin microbiome is considered important in skin health, the relationship between the skin microbiome and skin sensitivity is still unknown. Here, we aimed to (i) investigate whether the microbiome and mycobiome of SS are distinct from those of non-sensitive skin (NS), and (ii) define the characteristics of the skin microbiome associated with skin sensitivity. A total of 42 Korean women subjects were recruited (SS, n = 23; NS, n = 19) and the microbiome/mycobiome of their right facial cheeks were analyzed. We identified the differential microbiome and mycobiome structures between SS and NS. The mycobiome of SS was more phylogenetically diverse than that of NS. Lactobacillus and Mucor racemosus were more abundant on SS than NS, whereas Malassezia restricta was less abundant. Interestingly, both skin microbiome and mycobiome varied according to the perceived skin sensitivities of the subjects. This study suggests that the skin microbiome and mycobiome are associated with skin sensitivity. Accordingly, it lays the foundation for developing microbiome-based cosmetics or remedies for individuals suffering from SS syndrome.

Fungal Diversity in the Rhizosphere and Rhizoplane of Okra (Abelmoschus esculentus L.) Moench. in Nsukka, Enugu State, Nigeria

Aim: The growth and development of economically important crops are usually affected positively or negatively by the microbes present in the rhizosphere and rhizoplane. Based on this, the study was carried out to determine the fungal diversity in the rhizosphere and rhizoplane of okra plant. Methods: Okra seeds were purchased from an agricultural shop in Nsukka main market and were planted at Botanic garden, Department of Plant Science and Biotechnology, University of Nigeria, Nsukka. Physicochemical properties of the soil sample were evaluated prior to planting and as the plant aged. Rhizosphere and rhizoplane samples were collected at two weeks interval and dilution plate method was used in fungi isolation after which they were identified. The frequency of occurrence and the colony forming unit per gram of the sample (cfu/g) were evaluated. Results: The Physicochemical properties of the soil samples fluctuated as plant aged at two weeks intervals. The pH was slightly acidic to neutral which is ideal for most plant to grow. The water retention capacity, moisture content and organic matter content increased from 11.47-27.90 ml/g, 5.03-21.07% and 2.35-3.68% respectively at two weeks interval but fluctuates at subsequent weeks. A total of eleven (11) fungi were isolated from the rhizosphere and were identified as, Aspergillus niger, Aspergillus fumigatus, Aspergillus flavus, Aspergillus bertholletius, Fusarium oxysporum, Galactomyces candidum, Helminthosporium solani, Rhizopus stolonifer, Mucor racemosus, Penicillium citrinum and Trichoderma viride. All fungi were present in the rhizoplane except Aspergillus bertholletius and Penicillium citrinum. Rhizosphere had a greater number of fungi than the rhizoplane. Aspergillus species were predominant in both the rhizosphere and rhizoplane. A. niger had the highest frequency of occurrence of 58.67% on the 6th week and 65.79% on the 4th week in rhizosphere and rhizoplane respectively. The colony forming unit (cfu/g) of Aspergillus niger was significantly different from all other isolates at P≤0.001 followed by Mucor racemosus and Fusarium oxysporum with significant differences at P≤0.05 and P≤0.01 respectively. Conclusion: The rhizosphere and rhizoplane of okra plants has been shown to be rich in fungal diversity and a greater number were obtained from the rhizosphere. The data obtained from this work could be exploited by microbial ecologist to ascertain ecological associations and biomass increase by the fungal communities which also forms part of ecosystem. The fungi had no pathological effect on the plant which suggest positive effect on the growth and development of okra plant as the plant aged.