Biotechnology Journal International

Ethanol is an alternative fuel derived from renewable biological resources. It's a good substitute for gasoline in spark ignition engines. In this study, the sugar cane bagasse was chemically pretreated with 1% NaOH at room temperature for 2 hours. Dilute acid H₂SO₄ and Aspergillus niger was used to hydrolyse the biomass to sucrose. Fermentation of the hydrolysed sample was done using Saccharomyces cerevisiae. The fermented product was purified by distillation process at 78^oC, and the fraction was collected, and the ethanol was determined by measuring the specific gravity. The production of ethanol from sugar cane bagasse with Saccharomyces cerevisiae was determined after the inoculation into sample A₁, A₂ and B₁ and B₂ and highest ethanol produced were from B₁ with 0.090 followed B₂ 0.074, A₂ with 0.069% and D 0.116. The use of Saccharomyces cerevisiae gives a better yield. The result of this study can be of a better application in the large production of biofuel from sugar cane bagasse which is renewable and highly abundant, it is saving costs by recycling of wastes, and it also helps to alleviate environmental problem such as an excessive release of greenhouse gases from combustion of non-renewable fossil fuel. From the chromatograph, when the peaks spectrum wave analysed by mass spectrometer of the three volatile organic compounds, two were common to both samples, A contains the abundance of Acetic acid 22.37%, Ethyl alcohol 13.55% isobutene 64.08%. While that of Sample B contains the abundance Acetic acid 17.43%, Ethyl alcohol 7.12% and Propane 75.4.according to Pasteur this is due to Microbial oxidation of ethanol to acetic acid that decreases metabolic toxicity to the yeast cells. This study has proven the efficiency of Saccharomyces cerevisiae for the production of bioethanol.  

This study involved the molecular identification of Chlorella vulgaris microalgae obtained from Kaduna State University Fish Pond for biodiesel production potential. The DNA of Chlorella microalgae was extracted and subjected to PCR. The molecular weight of the PCR product obtained was 1.8kb using 18S rDNA primer sets and BLAST analyses revealed 95% identity with Chlorella vulgaris. The Chlorella vulgaris was cultured in open aquaria tanks at the Department of Biological Sciences, Nigerian Defence Academy. The biomass harvested was subjected to varying timings of sun and oven drying techniques (25-35ºC for 72hours and 60ºC for 12hours respectively) before extraction of oil from the biomass using solvent extraction method. The values for the density (0.854 and 0.867 cm³), specific gravity (0.875 and 0.876), acid value (0.414 and 0.384 mgKOH/g), saponification value (173.3 and 170.1 mgKOH/g), kinematic viscosity (5.200 and 3.870 mm²/g at 40ºC), flash point (114 and 115ºC) and cetane number (54.00 and 47.70) for the sun and oven dried biomass oil respectively were found to be in accordance with the ASTM standard values for biodiesel and fossil diesel. GC-MS analyses of the oil extracted using the two drying methods showed that the fatty acid profiling of the oil obtained from sun dried processed biomass had C14:0, C15:0, C16:0, C18:0, C18:1 cis9 and C22:1ω9 while the oven dried biomass oil had C14:0, C16:0, C19:0, C11:1, C18:1 cis9 and C22:1ω9. Drying methods, therefore, had influenced on the composition of saturated and unsaturated fatty acids. The oven dried biomass oil possesses high monounsaturated fatty acids when compared to sun dried biomass oil though the most important fatty acids (C14:0, C16:0 and C18:1) found in standard biodiesel were present in both. The results suggested that Chlorella vulgaris microalgae can be sustainably harvested for the production of biodiesel, both drying techniques can be employed for effective extraction but oven dried biomass oil was found to be of high quality because of the balanced in saturated and unsaturated fatty acid compositions and have an easy mode of operation but it required instrumentation.

The fruit of Astrocaryum aculeatum G. Mey. are consumed by population in the Brazil Northern resulting fruit peels. These peels are rich in lignocellulose and fat. The present study investigated peels from the Astrocaryum aculeatum G. Mey. as a substrate for lipases production by solid state bioprocess. To reach this objective: 1) we isolated fungi from peels from the fruit of Astrocaryum aculeatum  G. Mey; 2) we screened the isolates for lipase production (screening in petri dish and screening in submerged bioprocess), 3) we investigated the production of lipases by using peels from Astrocaryum aculeatum  G. Mey as substrate. The isolates belonged to the genera Aspergillus (16), Penicillium (3) and Fusarium (1). These strains were submitted to petri dishes and submerged fermentation for lipases production, these experiments resulted in the selection of five strains belonging to the Aspergillus genera. The lipases produced by these five strains performed enzymatic transesterification; however, the lipases from the strain Aspergillus niger A2B1 produced the highest ester content. The utilisation of fruit peel from Astrocaryum aculeatum G. Mey. as the main substrate, fruit peel from Astrocaryum aculeatum G. Mey. oil (13%), moisture (70%) and 75 h of incubation were the optimal conditions identified for the production of lipases by Aspergillus niger A2B1(17.42 U/g) in solid state bioprocess (SSB).

Aims: The process parameters affecting enzyme production were optimized to ascertain the best optimal conditions for β-mannanase production by Penicillium italicum in solid state fermentation.

Study Design: Four stages of experimental processes were designed for this study. The first experiment, samples were withdrawn after 24, 48, 72, 96, 120, 144,168 and 192 h incubation.  In second experiment, the fermentation media were incubated at different temperatures. In third experiment, the effect of different pH values on β-mannanase production was evaluated, while the fourth experiment described the supplementation of surfactants in mineral salt solution for β-mannanase production.

Place and Duration of Study: Microbiology Research Laboratory, Federal University of Technology, Akure Nigeria between September 2011 and March 2012.

Methodology: β-mannanase production was conducted using Locust Bean Gum (LBG) as the sole carbon source; moisten with mineral salt solution, and enzyme activity determined by dinitrosalicylic acid method, while protein content was determined by Lowry method.

Results: Maximum enzyme activity (146.389 U/ml) was observed after 72 h of incubation. Different surfactants were supplemented in the basal medium, and Sodium Dodecyl Sulfate (SDS) was observed to give the highest β-mannanase activity of 53.335 U/ml. Initial pH of the culture medium was optimized and a pH of 6.0 was found to support maximum enzyme activity (173.241 U/mg protein). The optimum incubation temperature was achieved at 35°C.

Conclusion: The results obtained provide information on optimal process parameters that might improve the yield of β-mannanase by P. italicum for better fish feed formulation, especially in the larval stages of fish fingerlings when the enzyme system is not efficient.

A large amount of crude oil is spilled annually into the terrestrial and aquatic environments in Nigeria. This tends to upset the natural equilibrium of the marine environment as a microbial habitat. Thus, there is a need to evaluate the effect of exposure to crude oil on bacterial load and diversity using Iko River and Odoro Ikot pond as the study and pristine sites respectively. The bacterial isolates were molecularly identified using the 16S rRNA sequencing protocol. The total heterotrophic bacterial count (THBC) in the surface water (SW), sub-surface water (SSW) and sediment segments of Iko River ranged from 2.23±0.87 to 9.67 ± 0.43 x 10⁶ CFU/ML while the THBC in the SW, SSW and sediment segments of the pristine site (Odoro Ikot pond) ranged from 1.87±0.53 to 4.8± 0.04x10⁶ CFU/ML. The sediment had a significantly higher (P<0.05) THBC than the water segments (SW and SSW) in both Iko River and Odoro Ikot pond. The hydrocarbon utilizing bacteria (HUB) count in Odoro Ikot pond ranged from 0.40 ± 0.01 to 1.10 ± 0.03 x 10⁶ CFU/ML while the HUB count in Iko River ranged from 0.53 ± 0.02 to 0.93 ± 0.04 x 10⁶ CFU/ML, making Iko River have a higher number of total heterotrophic bacteria and hydrocarbon utilizing bacteria than Odoro Ikot pond. The Proteobacteria isolates had the highest bacterial diversity (77%) while members of the Firmicutes phylum had a 23% bacterial diversity. However, higher bacterial count and diversity were obtained from the sediment segment than from the water segments in both Iko River and Odoro Ikot pond implying that the sediment is more favourable for bacterial growth. Although the bacterial profile was affected by exposure to crude oil, there were variations in the phylogenetic diversities obtained from the different water segments attributable to crude oil concentration.