Journal of Advances in Biology & Biotechnology

The general objective of this work was to highlight the physiological phenomenon of photosynthesis that underlies ripening in banana fruits and to follow its bioindicators evolution. To achieve this goal, pigment content, protein content and the amount of oxygen released were determined at different stages of ripening of bananas fruits. The determination of pigment content was carried out by spectrophotometric assay after extraction in pure acetone. Protein content was determined using a known albumin concentration calibration curve. Moreover, photosynthetic intensity was evaluated by measuring the oxygen released by the banana peels by means of an oximeter. Results showed that there was a gradual decrease in pigment levels, while at the same time there were increases in carotenoid and protein levels. Photosynthetic intensity and capacity also decreased significantly. The treatment of bananas with calcium chloride helped to slow the fall of photosynthetic activity. Also, calcium chloride treatment induced a reduction of the decrease in chlorophyll content, photosynthetic intensity and increase in proteins content. Positive correlations were found between photosynthetic intensity and levels of chlorophyll a and total chlorophylls. The intensity of photosynthesis was negatively correlated with carotenoid and protein levels. The change in photosynthetic intensity during ripening was proportional to the variation in chlorophyll a and total chlorophylls content, but inversely proportional to variations in total carotenoids and proteins contents.

Aim: The aim of the study is to evaluate the Protective role of Lycopene on hormonal profile and posttesticular functions of male rats exposed to sublethal doses of Cypermethrin.

Study Design: The study was a completely randomized design employing relevant statistical tools for analysis and interpretation.

Place and Duration of Study: The study was carried out in the Reproductive Physiology and Genetics Research Laboratory of the Department of Applied and Environmental Biology, Rivers State University, Rivers State. The experiment lasted for 35 days.

Methodology: For the sperm morphology assay, sperm reserves and hormonal profiling, semen samples were drawn from the caudal epididymis with a syringe and placed on a clean glass slide. A drop of freshly prepared eosin-Y was added to make a thin smear and examined under the microscope for morphological abnormalities. A portion of the testis and epididymidis was homogenized separately with sharp pointed scissors in normal (physiological) saline. The suspension was mixed and strained through a double layer of sterile cheese cloth into graduated test tubes. All the samples were covered and stored for 24 hours at 4⁰C. A dilution was made for counting in Neubauer haemocytometer. The hormonal concentration was determined using the Randox Monza Laboratories assay kit from Co-Atrim, United Kingdom. 

Results: Results of oral administration of Cypermethrin and co-administration of lycopene in rats showed Group G co-administered pure Lycopene had the lowest sperm head abnormalities of 3.5%, group B administered Cypermethrin only had the highest head abnormalities of 44.7%. Similarly, Group G, co-administered pure Lycopene had the lowest percentage of tail abnormalities of 10.1%  while Group B had the highest percentage of sperm tail abnormalities of 32.4%. There was a was significant (p<0.001) decrease in concentration of all androgens considered in group B administered Cypermethrin only.

Conclusion: Exposure to Cypermethrin only as in group B disrupted the production of all androgens considered, increased the percentage of abnormal spermatozoa, reduced sperm motility, viability and sperm reserves. However, results recorded from the co-administration of Solanum lycopersicum and pure lycopene, in groups C-G indicate the protective role of this potent antioxidant on spermatogenesis and hormonal profile.

Fungal laccases are preferred due to high redox potentials and low substrate specificity to xenobiotics including synthetic dyes. For large-scale applications, low enzyme yield and high cost of production has remained the challenge. Agroindustrial waste such as saw-dust of Terminalia superba abounds locally and was utilized as low-cost alternative substrate for laccase production in Solid State Bioprocessing (SSB) using Trametes sp. isolate G31. The study optimized laccase production using various parameters. Optimal production of laccase was at pH 5.0 - 7.0 with 2356 U/mL - 2369 U/mL and 25°C (2336 U/mL). Among the sources of nitrogen and carbon tested, laccase production in ammonium sulphate and sucrose supplemented media were higher. The effect of activators on laccases production showed that Cu²⁺ and Ca²⁺induced high titres of laccase at 4 -5 mM and 2 - 4 mM respectively, while production of laccase by Mn²⁺ was significantly high at 40 mM. The effect of 2, 2-azino-bis (3-ethylbenzthiazoline-6-sulphonic acid) (ABTS), guaiacol and varatryl alcohol on laccase production was significantly different especially in glycerol. Optimum production for laccase was on day 14 with 2356 U/mL followed by steady declined up to day 34. The purified laccase had a specific activity of 5008 µmol/min/mg, purification factor of 3.85, and a molecular mass of ~40 kDa using N-PAGE. The potential of crude laccase to decolourize diverse dyes was tested. Phenol red achieved 40% decolourization for 1hr, while RBBR (93%), Crystal violet (60%), Methylene blue (53%) and Congo red (51%) for 24 hr, 72 hr, 48 hr and 120 hr respectively. Methyl red and Malachite green attained 42% (72 hr) and 32% (48 hr) decolourization. The enzyme ability to oxidize Phenol red and other synthetic dyes without mediators made it eco-friendly in treating dye wastewaters.

Aims: The importance of nutritional and environmental factors in the production of microbial enzymes cannot be overemphasized. Hence, endo-β-mannanase production was systematically studied in a step-wise approach of building up on the experimentally observed conditions favouring the production of this enzyme in Aspergillus flavus PT7.

Place and Duration of Study: Department of Microbiology, University of Ibadan, Nigeria, between January 2018 and December 2018.

Methodology: Thirty-eight (38) fungal isolates obtained were screened for mannolytic ability using standard method. The highest producer of endo-β-mannasase was subjected to various production conditions by adjusting the nutritional and environmental factors in view of optimizing the production of this enzyme in the isolate Aspergillus flavus PT7.

Results: Copra meal was the highest inducer of mannanase production in the isolate at enzyme activity of 85.86±3.93 U/gds. Production increased to 94.54±0.42 when all forms of extraneous nitrogen sources were excluded from the production medium. pH 5.0, temperature 30°C, moisture content at 100% v/w and inoculum size of 8.0% v/w led to the increase in production by 44% (enzyme activity of 153.24±5.69 U/gds) in 5 days of incubation. Allowing the production set up additional two (2) days led to production increase with a recorded enzyme activity of 170.34±4.35 U/gds. Production of endo-β-mannanase in A. flavus PT7 was observed to be inductive as the presence of simple sugars like glucose, galactose, arabinose and xylose led to extended lag period in the production of the enzymes by the isolate.

Conclusion: Production of endo-β-mannanase by Aspergillus flavus PT7 was successfully optimized in a step-wise and systematic experimental study of the nutritional and environmental growth conditions of the isolate.

Background: Soil Electrical Conductivity (EC) is one of the soil physical properties related to a number of soil indices either in it natural status or anthropogenic influenced condition within individual field or across soil landscapes such as the tripartite ecological condition under consideration.

Aim: The study was aimed at understanding the varying relationship between soil EC and ionic-salinity changes under ecological tripartite condition of pre-pollution, post-pollution and phytoremediation soils.

Study Design: Research methods involved the nested split plot design, carried out the Department of Botany, University of Calabar, Cross River State, Nigeria.

Methods: Field sampling / laboratory analysis and SAS PROC. ANOVA (Soft Ware) for data analysis.

Results: Has revealed increasing trend of Nitrate (NO₃^-), Phosphate (PO₄^-), Calcium (Ca²⁺), Potassium (K⁺), salinity and EC and a decreasing trend of Sulphate (SO₄^-), Magnesium (Mg²⁺), Sodium (Na⁺), and moisture in post-pollution. Macrophytic treated hydrocarbon soils had decrease in NO₃^-, Ca²⁺, Mg²⁺, salinity and EC and increase in SO₄^-, PO₄^-, Na⁺, K⁺, and moisture  in divergence content. Peltophorum soil was greater in NO₃^-, SO₄^-, and K⁺, Leucaena soil in Ca²⁺, Mg²⁺, PO₄^-, and moisture while Crotolaria was high in Na⁺, and salinity content.

Conclusion: The trend observed for EC in the phytoremediation phase of the tripartite condition paralleled changes in ionic content and salinity strength. Therefore EC is a function of ionic dynamics, salinity and moisture which appears to be reliable indicator of EC potential of tripartite soil.