Open Access Short Research Article

Studies on Removal of Heavy Metals from Tannery Effluent by Native Isolates of Bacteria and Fungi

M. D. Makut, A. Gimba, A. Bello

Asian Journal of Biotechnology and Bioresource Technology, Page 1-8
DOI: 10.9734/AJB2T/2018/41884

Studies on Removal of Heavy Metals from Tannery Effluent by Native Isolates of Bacteria and Fungi

Aim: This research work is aimed at studies on removal of heavy metals from tannery effluent by species of bacteria and fungi.

Study Design: This study is designed to isolate and identify bacteria and fungi from tannery effluents, to determine the concentration of heavy metal in tannery effluent, to assess the removal of heavy metals by bacteria and fungi from tannery effluents, to assess the effect of temperature and pH on heavy metal removal.

Place and Duration of Study: Department of Microbiology, Nasarawa State University Keffi, Nasarawa State, Nigeria, between January 2017 and December 2017.

Methodology: A total of four (4) tannery effluents samples were obtained from Challawa industrial area in Kano, Nigeria. Bacteria and fungi were isolated from the effluent and identified using standard microbiological methods. The heavy metal content of the effluent was determined using Atomic Absorption Spectrometer. The heavy metal removal capacity by bacteria and fungi was also determined at different temperatures and pH.

Results: The bacteria isolated from the effluent were Bacillus subtilis and Pseudomonas aeruginosa and the fungal isolates were Penicillium notatum and Aspergillus niger. The identified heavy metals were Chromium, Cadmium, Copper, Lead, Zinc and Iron. The bacterial and fungal load of the tannery effluent were within the range of; bacteria (2.9-4.3×105 Cfu/L) and Fungi (5.0×10 4- 1.0 × 105. Cfu/L). Out of the samples of tannery effluent obtained, the occurrence of Pseudomonas aeruginosa, Bacillus subtilis, Penicillium notatum and Aspergillus niger were 100%.  The result of the study revealed that the values for the metals were above the maximum permissible limits of both the Nigeria Standard of Drinking Water (NSDW) and World Health Organization (WHO). All isolated organisms showed an affinity for Pb, Cu, Cr and Zn.

Conclusion: From this study, it can be deduced that bacteria and fungi have a high capacity for removal of metal from tannery effluents. However, there is a need for further work to be done to validate and improve these findings.

Open Access Short Research Article

Production of Xanthan Gum Using Xanthomonas campestris Isolated from Some Plants Leaves in Keffi, Nigeria

M. D. Makut, P. E. Agbonkhese, A. Bello

Asian Journal of Biotechnology and Bioresource Technology, Page 1-9
DOI: 10.9734/AJB2T/2018/42025

Production of Xanthan Gum Using Xanthomonas campestris Isolated from Some Plants Leaves in Keffi, Nigeria

Aim: This research is aimed to produce xanthan gum using Xanthomonas campestris isolated from some plant’s leaves in Keffi, Nigeria.

Study Design: To isolate and identify Xanthomonas campestris from some plant leaves (mango, orange, rice), to produce xanthan gum using Xanthomonas campestris, is done to determine the effects of fermentation time, temperature, pH, and carbon source on xanthan gum production by Xanthomonas campestris isolates.

Place and Duration of Study: Department of Microbiology, Nasarawa State University Keffi, Nasarawa State, Nigeria, from January 2017 to December 2017.

Methodology: Leaves with dark rot spots were collected from Keffi area of Nasarawa state, Nigeria. Xanthomonas campestris was isolated from the leaves were collected from Malt, Yeast Medium(YM), by following standard microbiological methods. Potato peel starch substrates extracted from potato peels were used as fermentation medium for the production of xanthan gum. The effect of time, temperature, pH and carbon source on xanthan gum production were observed.

Results: Xanthomonas campestris were isolated from plants leaves in Keffi and they were able to produce xanthan gum. It was also observed that 72 hours, 30°C, pH 6.0, potato peel substrate concentration 10% and sucrose as carbon source were the optimal factors  for production of xanthan gum using Xanthomonas campestris.

Conclusion: From this study it can be deduced that Xanthamonas spp isolated from leaves in Keffi are capable of producing Xanthan gum at optimal conditions, further studies to standardize the inoculum and medium for xanthan gum production is necessary to achieve a product of greater and better quality.

Open Access Original Research Article

Effect of Inoculum Type on Anaerobic Co-Digestion of Palm Oil Mill Effluent and Brewery Spent Grain for Biogas Production

Utibe Amos Ofon, Uduak Ugonma Ndubusi-Nnaji, Naomi Udo Asamudo

Asian Journal of Biotechnology and Bioresource Technology, Page 1-11
DOI: 10.9734/AJB2T/2018/41058

The effect of different inocula on the anaerobic co-digestion of palm oil mill effluent (POME) and brewery spent grain (BSG) was evaluated for biogas production using laboratory scale bioreactors. The reactors (A: POME + BSG + cow dung, B: POME + BSG + swine dung, C: POME + BSG + swine dung + cow dung) were incubated at 35 ± 2°C for 30 days. The average biogas volume measured periodically by water displacement technique were 4.73, 38.64, and 36.45 mL gVS⁻¹ in reactors A, B and C respectively. The results indicated that reactor B produced 8.17 times more biogas than A and 1.06 times than C, whereas reactor C produced 7.71 times more gas than A, with significant differences at p = 0.05. The acidity of the digestates increased with a decrease in pH from 6.91 to 4.52, 7.33 to 5.20, and 6.73 to 5.46 in digesters A, B and C respectively. Whilst the total solid contents decreased from 18.22 ± 0.22 to 9.27 ± 0.01%, 19.05 ± 0.13 to 9.26 ± 0.01%, and 18.88 ± 0.03 to 8.62 ± 0.04%, volatile solids reduced from 10.9 ± 0.16 to 0.04 ± 0.01, 10.7 ± 0.07 to 0.28 ± 0.34, and 10.8 ± 0.09 to 0.09 ± 0.04% in reactors A, B and C respectively. The total anaerobic bacterial loads of reactors A, B and C respectively were 5.57± 0.46, 5.61 ± 0.39, 5.38 ± 0.48 Log₁₀ CFU g⁻¹. Methanogens associated with the biogas production were identified as members of the genera Methanothrix, Methanosarcina, Methanobrevibacter and Methanocorpusculum. Contrary to using cow dung only as inoculum, the combined use of swine and cow dung for anaerobic co-digestion enhanced biogas production and/or yield.

Open Access Original Research Article

Phenylpropanoid Pathway Response to Cadmium and Lead Stress in Phaselous vulgaris Roots and Leaves

Zehra Tavsan, Hulya Ayar Kayali

Asian Journal of Biotechnology and Bioresource Technology, Page 1-11
DOI: 10.9734/AJB2T/2018/40759

Phenylpropanoid Pathway Response to Cadmium and Lead Stress in Phaselous vulgaris Roots and Leaves

Heavy metals induce diverse morphological and physiological changes in plants, but the actual mechanisms leading to integrated responses are not well understood. For better understanding, the metabolic adaptation to Cd and Pb stress in Phaseolus vulgaris, the alterations in the phenylpropanoid pathway related enzymes, shikimate dehydrogenase (SKDH) and phenylalanine ammonia lyase (PAL), and also total phenolics and flavonoid contents were studied in the roots and leaves. It was found that Cd and Pb treatments caused an increase in the activities of SKDH and PAL, and in the content of total phenolics and flavonoids. In the roots and leaves of Cd-treated plants, SKDH activities were induced by low concentrations, while the highest activities were observed in the roots treated with Pb and in contrast, were inhibited in the leaves. PAL activity showed similar alterations in a dose-dependent way both Cd and Pb-treated roots and leaves of P. vulgaris. After the 3rd day, the decreases in the enzyme activities, and total phenolics and flavonoids content suggest that the stricter mechanism than phenolics, lignin synthesized from the accumulated phenolics to overcome metal-induced stress. Taking all the data together, it was demonstrated in this work that phenylpropanoid pathway was actively regulated by P. vulgaris plants in response to heavy metal stress.

Open Access Original Research Article

Effects of Gamma Irradiation on Some Growth Traits and Yield Attributes of Pigeon Pea ‘Fiofio’ [Cajanus cajan (L.) Mill sp.]

Aibuedefe Osagie Eremwanarue, Udensi Ugorji

Asian Journal of Biotechnology and Bioresource Technology, Page 1-8
DOI: 10.9734/AJB2T/2018/42180

Effects of Gamma Irradiation on Some Growth Traits and Yield Attributes of Pigeon Pea ‘Fiofio’ [Cajanus cajan (L.) Mill sp.]

Conventional breeding methods such as mutation breeding could lead to an improvement in the genetic variability in local varieties. The objective of the study was to evaluate the effect of gamma irradiation on the growth traits and yield attributes in two pigeonpea landraces (Cajanus cajan (L.) Millsp); white and brown varieties with the native name "fiofio" as used in the eastern part of Nigeria. Seeds of the landraces were obtained from the germplasm collection of the Department of Genetics and Biotechnology, University of Calabar, Nigeria. These seeds were irradiated with 0, 200Gy, 400Gy and sown in a plot measuring 10 × 10 meters at the University of Calabar Experimental Farm during 2011 growing season. A Randomized Complete Block Design (RCBD) was adopted during the planting. The result obtained revealed that percentage seed germination was not significantly affected (P>.05) by the gamma irradiation when compared to the control. But at the varietal level, white variety seeds exposed to 200Gy gamma irradiation recorded the highest percentage germination. The growth traits and yield attributes showed there were significant differences (P< .05) in all parameters studied except percentage germination while all seeds exposed to 400Gy did not survive more than two and half  months after germination. It was observed that there were variation between the two varieties under study, brown pigeonpea treated with 200Gy were more adversely affected as white pigeonpea treated with 200Gy was the overall best performing variety even when compared to both white and brown controls. This vividly revealed that gamma irradiation sufficiently encourages the improvement of these crops.