Asian Journal of Biotechnology and Bioresource Technology

Aims: To investigate the effect of temperature on the mycelial growth of the highly prized mushroom, Tricholoma matsutake, in soil medium.

Methodology: Seven strains of T. matsutake collected from different areas of Japan were incubated in soil medium at 5, 10, 15, 20, 25, and 30°C for 89 day. After incubation, the linear growth of mycelia from the inoculum was measured on vertical lines under a dissecting microscope and classified by the cultivation day number to obtain the growth rate in each vial. The mycelial densities in the soil medium in all the vials were analyzed using qPCR to determine the mycelial biomass.

Results: The mycelial growth of T. matsutake strains was mainly observed at 5–25°C. The optimum temperatures for linear mycelial growth and for the increase in mycelial density were 19.6°C and 17.6°C, respectively. These values were lower than those reported previously for T. matsutake grown on agar medium or in liquid medium. These optimum temperatures showed no clear relationship with the mean air temperature at the site of strain collection.

Conclusion: It can be suggested that a temperature around 18°C is suitable for cultivation of T. matsutake mycelia in the soil medium.

Inbreeding is defined as the probability that two alleles at any locus are identical by descent and occur when related individuals are mated to each other. A total of 123427, 115810 and 88361 records of 412-d yields of milk, fat and protein of Iraqi Holstein cows were collected from 1995 to 2010 in 838 herds used to estimation the inbreeding depression and inbreeding trend. Pedigree records of Iraqi Holstein cow were used to assessment inbreeding coefficients and these coefficients ranged from 0 to 42%. Animal model was used to estimation inbreeding depression on traits. Fixed effects included in statistical model were herd – year, age at calving and inbreeding coefficient as continuous and discrete variable. When considering inbreeding as continuous variable in model, the inbreeding depression for 412-d yields of milk, fat and protein were -28.19, -0.98 and -0.88 kg per 1% increase in inbreeding in Iraqi Holsteins, respectively. In this group of animal that inbreeding coefficient was between 0 < F ≤ 5.34 inbreeding was not caused reduction in production traits. However, in group of animal that inbreeding coefficient was greater than 5.34, and inbreeding depression in production traits was observed. The result of this study confirms of inbreeding depression in Iraqi Holstein cows.

The aim of this study was to optimize the hydrolytic activity of A. niger α-amylase on cassava starch. Isolation of Aspergillus niger, determination of α-amylase activity, α-amylase production and extraction were performed using standard protocols. Parameters such as pH, temperature, substrate concentration were studied using unifactorial approach. pH was varied from 3.6-5.6, temperature 30-80ºC, substrate concentration 0.3-1.5 g/l. In conclusion, for optimal utilization of α-amylase in the production of numerous products of economic significance, the outcome of this work can be relied upon to boost production of glucose and accessory products from starch.

Balanites aegyptiaca has been used in many traditional treatments of microbial infections. This work was carried out with the aim of determining the phytochemical compounds present in the ethanolic extracts of the root, stem and leaves of Balanites aegyptiaca and their effects against selected microorganisms. Phytochemical screening was undertaken to determine presence of secondary metabolites in the stem-bark, roots and leaves of the test plant. Well diffusion method was used to determine sensitivity of test organisms to the test plant. Result indicated the presence of alkaloids, tannins, flavonoids, saponins, steroids, and anthraquinones, although anthraquinones were absent in ethanolic extracts of root and stem bark of Balanites aegyptiaca but present in the ethanolic extract of the leaf. Antibacterial effects were tested against Staphylococcus aureus and Klebsiella pneumoniae. Results obtained from the ethanolic extract of the root stem and leaves showed significant zones of inhibition against Klebsiella pneumoniae and Staphylococcus aureus at all concentrations of 100 mg/ml, 50 mg/ml, 25 mg/ml, 12.5 mg/ml and 6.125 mg/ml. The positive control performed better than the extracts in terms of zone of inhibition. The results of the minimum inhibitory concentration (MIC) indicated that the leaf ethanolic extract had the greatest activity against K. pneumoniae with MIC value of 12.5 mg/ml, while the results from the minimum bactericidal concentration (MBC) showed that the leaf ethanolic extract had the greatest activity against K. pneumoniae with an MBC value of 12.5 mg/ml.

A study was conducted to evaluate the effect of processing methods on the antinutrients and amino acids composition of Balanites aegyptiaca. The durations for soaking, roasting and fermentation were 0, 24, 48, 72 and 96 hours to determine the optimal duration of inclusion of processed Balanites aegyptica. Raw and processed samples were analysed for amino acids composition and anti-nutritional factors.The trial showed a linear increase in processing duration resulted into a decrease in the concentration of antinutritional factors. Raw Balanites aegyptica had higher concentration of concentration of amino acid than the soaked and boiled Balanites aegyptica. Soaking, fermentation and boiling up to 96 hours reduced the antinutritional components of Balanite aegyptica. Percentage reduction of anti-nutrients in Balanites aegyptica. fruit meal was best at 96 hours of soaking and fermentation and 60 minutes of boiling and roasting. All anti-nutrients in Balanites aegyptiaca fruit meal showed remarkable reduction post processing. In all processing methods, results showed that anti-nutrients in the Balanites aegyptiaca reduced up to the maximum durations of processing (96 hours and 60 minutes). It was therefore advisable to include  Balanites aegyptiaca upto 96 hours in the diets of broiler birds.

Discharge of poorly treated refinery wastewater has always been a major environmental challenge. Bacterial immobilization is key to the maintenance of biomass on a contaminated site. In this study, a mixed culture of three bacterial isolates from oil-polluted water: Pseudomonas aeruginosa (MN294989), Bacillus tequilensis (MN294990) and Micrococcus sp. immobilized on Groundnut Shell (GS), Melon Husk (MH) and Sugarcane Bagasse (SB) were employed in the bioremediation of Port Harcourt refinery wastewater. Surface area and pore size distribution of the agro-based bio carriers were suitable for bacteria adhesion. The bacterial isolates were screened for phenol, naphthalene and hydrocarbon utilization. Scanning Electron Microscopy (SEM) was used to ascertain the immobilization of the consortium on the agro-base carriers. A 15-days laboratory-scale treatment of refinery raw wastewater was compared in the immobilised and immobilized consortium. The agro-based residue immobilized consortium enhanced the reduction in BOD₅, COD, oil and grease, phenol by 7%, 9%, 30% and 5% respectively compared to the free form of the consortium. This study underscores the role of immobilization in maintaining high bacterial biomass on contaminated site and possible improvement in bioremediation of refinery wastewater.