South Asian Journal of Research in Microbiology

The fermented solution of this strain contains the highest concentration of citric acid, indole acetic acid (IAA) and elements as well as phosphatase activity. Using the Aspergillus tubingensis USMI03 RPf10 fermented solution as a medium led to decrease in the growth rate of tested bacterial isolates (Bacillus subtilis, Pseudomonas fluorescens and Escherichia coli) and fungal isolates (Aspergillus sp. and Penicillium sp.) except Trichoderma viride which gave the same growth on fermented solution treatments compared to control. Whereas the tested yeast isolates (Candida olivera and Saccharomyces cerevisiae) recorded the same growth rate on fermented solution treatments as whole media and higher growth rate on fermented solution + glucose treatment, compared to control. Also, the latter treatment resulting in higher growth of some tested bacteria (B. subtilis and P. fluorescens) and the same growth rate of other bacteria (E. coli), compared to synthetic media. The growth of Rhizopus sp. decreased on fermented solution treatments than control. It is suggested that, using A. tubingensis USMI03 RPf10 fermented solution as a whole medium or as a mineral could be used as a source for microbial growth which varied from one microorganism to another.

Aims: To determine the toxic effect of refinery industrial effluents using three toxicity bioassays.

Study Design: Five treatments and the controls designs were set up in triplicates containing 6.25%,12.5%, 25%, 50%, 100% and 0% of the industrial effluents and incubated at 24°C for 0 - 96 h. The five treatments and control set ups designated as PH, Warri and Control (Without effluent) were used to determine the toxic effect of industrial effluents.

Place and Duration of Study: Department of Microbiology, Faculty of Natural Sciences, Chukwuemeka Odumegwu Ojukwu University, Uli Nigeria between September, 2019 and December, 2019.

Methodology: A laboratory scale study was carried on two composite samples of the produced water samples from the two studied areas using physicochemical analyses, microalgal toxicity test, mollusk toxicity and Zea mays test.

Results: The results revealed that Port Harcourt refinery effluent contains higher quantities of physicochemical parameters than the Warri effluent sample. Warri sample had the most harmful effects on Selenastrum capricornutum, Lymnaea stagnalis and Zea mays, with ErC₅₀ values of 47.62%, LC₅₀ of 51.86% and EC₅₀ of-32.68%, respectively. Inhibition (%) and mortality (%) of all species used were found to be concentration dependent with a significant (P < 0.05) strong positive correlation at increasing concentrations of industrial effluents.

Conclusion: Thus, these raw industrial effluents from Port Harcourt and Warri refineries are toxic and induced growth inhibition, mortality and phytotoxicity and adequate measures should be taken by these industries to minimize their negative environmental impacts.

Seed germination is the basis and initial stage in the process of plant growth and development. Bacillus subtilis QM3 is a plant growth promoting rhizobacterium (PGPR) with function of growth promoting, promoting, prevention of pathogens and pests attack and can improve plant resistance to different stress factors. Through the measurement of the early germination rate of wheat (Triticum aestivam L.). seeds under B. subtilis QM3 treatment, the results showed that B. subtilis QM3 can significantly promote the germination of wheat seeds, which has reached a significant level at 6h after seeds sowing or at 6 h of treatment, during imbibition. The β-amylase isoenzyme in early period of wheat seed germination was measured by denaturing polyacrylamide gel electrophoresis. The results showed that the band width and brightness of β-amylase isoenzyme of wheat seeds treated with B. subtilis QM3 increased during three to 6 h of imbibition and especially the effect was significant at 6 h. In the early period, the band of α-amylase isoenzyme could not be detected. It is suggested that the increase of β-amylase isoenzyme early band may be one of the main reasons for B. subtilis QM3 to promote wheat seed germination. Through the combination of B. subtilis QM3 with free and binding states of β-amylase, it was found that the former can increase the activity of β-amylase by either increasing free β-amylase or releasing binding β-amylaseisoenzyme. β-amylaseisoenzyme inhibitors can significantly inhibit β-amylase activity, nevertheless α-amylase activators and inhibitors have no significant effect on β-amylaseisoenzyme, which further proved that the β-amylase exerted the effects in the early period of wheat seed more precisely during the imbibition of the seeds.

This study was carried out to detect Salmonella species and evaluate the public health implications from different water sources in Keffi, Central Nigeria. A total of 100 water samples, 25 each of well, public borehole, tap and sachet water were collected from different locations within the Metropolis and analysed using standard microbiological techniques. Of which 38(38.0%) of the samples were contaminated with Salmonella species. The frequency of isolation shows that well water is the most contaminated, 18(72.0%), followed by borehole water, 10(40.0%), tap water, 7(28.0%), while sachet water is the least contaminated with an isolation rate of 3(12.0%). The total bacterial count ranged between 1.0–6.2 ×10³ cfu/ml, while the Salmonella/Shigella count ranged from 0.2–2.8×10³ cfu/ml. The total bacterial count of 6.2×10³ cfu/ml was recorded for well water, 2.2×10³ cfu/ml for borehole water, 1.2×10³ cfu/ml for tap water and 1.0×103 cfu/ml for sachet water, while highest Salmonella/Shigella count of 2.8×103 cfu/ml was recorded for well water. The pH for well and borehole water were slightly acidic, although that of tap (7.0) and sachet water (7.5) were within permissible limits. The temperature for the water samples were between 25°C–28°C. Meanwhile, turbidity was highest for well water (0.36NTU), in the same vain, total dissolved solid was highest for well water (16.12 mg/l) and lowest for sachet water (0.02 mg/l); while hardness of water was highest amongst the well water samples analysed with a measurement of 48.14 mg/l. The chemical properties of the water samples analysed showed the highest measurements of 6.80 mg/l, 0.78 mg/l and 3.48 mg/l of magnesium, iron and sulphate for well water respectively. Consequently, the presence of microbial contaminants particularly enteric pathogens is indicative of faecal contamination and this can lead to adverse health effects, including gastrointestinal illness and typhoid fever. Therefore, water in Keffi should be properly treated before consumption while boreholes and wells should be dug far away from latrines and septic tanks so as to avoid cross-contamination by faecal materials.

Forensic science is the application of science to civil and criminal laws, also called as “criminalistics”. Its branches are rooted in every branch of science and many other aspects of modern society. Forensic scientists are responsible to analyze scientific evidence during the course of investigation either by travelling to the scene of the crime or by performing analysis on objects in the laboratory. Forensic microbiology is the science by which microorganisms ‘behaviors are used to determine the origin of a particular microbial strain, the path of an outbreak or the identity of a criminal. Recently there has been a significant development in forensic microbiology as a result of the significant development in molecular biology, microbiology and biochemistry sciences. It was found that the rapid identification and classification of infectious microorganisms are of great importance in the case of biological and microbial threat, and the analysis of the microbial genome sequence, whose cost has decreased significantly in recent years, greatly helps in this area.