Annual Research & Review in Biology

This study investigated the effect of processing methods, temperature and storage days on the physico-chemical characteristics of snail meat products. Four different treatments were carried out; unseasoned fried (USF), seasoned fried (SF), seasoned oven- dried (SOD) and seasoned smoke- dried (SSD) snail meat products and were  stored under room, fridge and freezer storage conditions;  physico-chemical determination and analysis of variance were carried out. The results showed that the highest crude protein was obtained in the seasoned smoke-dried product (76.87%), followed by seasoned oven-dried product (75.80%), next was seasoned fried (70.15%) and the least was unseasoned fried product (68.57%). The highest ash value was seen in seasoned smoke-dried product (4.84%), followed by seasoned oven-dried (4.313%) and the least was unseasoned-fried product (3.933%). The highest energy values were observed in the fried products (1497.67 KJ/100 g seasoned fried and 1490.53 KJ/100 g unseasoned-fried).The highest iron value (16.47 mg/100 g) obtained was from seasoned smoke-dried product. Seasoned smoke-dried product was significantly different from other products and it had the highest mineral content. Seasoned oven-dried snail meat product had the lowest pH values 6.0, 7.17 and 6.29 for 0-5 days, 10-20 days and 25- 30 days storage respectively. This was followed by seasoned smoke-dried product having 6.68, 7.81 and 6.56 at 0-5 days, 10-20 days and 25-30 days respectively. The observed low pH in seasoned products could be ascribed to the effect of the seasonings; this is an indication of better shelf stability. It was observed that the combine effect of seasonings, smoke-drying and cold storage help to extend the shelf life of snail meat.

Aims: To explore the phylogenetic framework of bacteria isolated from contaminated marine environments of Niger Delta and the expression of the metabolic genes coding for aromatic hydrocarbon degradation and surfactant production.

Study Design: Nine treatments designs were set up in triplicates containing 25 mL of sterile modified mineral basal medium supplemented with nine marine hydrocarbon degraders incubated at 24°C for 5 days. Three of the set ups were supplemented each with 1 mg /L of xylene, anthracene and pyrene.

Place and Duration of Study: Department of Environmental Sciences, University of South Africa, Pretoria, South Africa between September, 2015 to December, 2017.

Methodology: A laboratory scale study was carried on six composite samples of the sediment and water samples from the three studied areas using enrichment, screening, selection, characterization, and PCR assays to explore the phylogenetic framework and metabolic genes expression of the marine bacteria for aromatic hydrocarbon degradation and surfactant production.

Results: The findings revealed that there was significant abundance of THB (P = .05) more than TCHUB and more xylene degraders than anthracene and pyrene degraders in the sediment and water samples respectively. The phylogenetic correlational analysis revealed that all the nine selected best degraders out of 48 isolates from the studied area were evolutionary related belonging to the genera: Providencia, Alcaligenes, Brevundimonas, Myroides, Serratia, and Bacillus; able to significantly (P = .05) utilize the all the aromatic hydrocarbons. The existence of catabolic and surfactant genes namely catechol dioxygenase (C23O), rhamnolipid enzyme (rhlB) and surfactin /lichenysin enzyme (SrfA3 /LicA3) genes were detected in only four (4) out of the nine (9) marine aromatic degrading bacteria  with 881 base pairs sizes.

Conclusion: Thus, the study revealed that these bacterial strains especially Serratia marcescens XYL7 might possess metabolic genes for in situ aromatic hydrocarbon degradation and surfactant production.

A comparative study on the growth performance of African catfish (Clarias gariepinus) fed shrimp based diet (SBD), chicken offal based diet (COBD) and coppens feed was carried-out for 22 weeks in concrete tanks measuring 3.5 x 1.7 x 1.5 m³. Triplicate groups of 40 juveniles with average length of 9.15 ± 0.17cm and weight of 20.00 ± 2.58g were stored in each tank. A total of 360 juveniles were used throughout the study. Fish were fed daily at 3% of their body weight through-out the duration of the experiment. The nutrient composition of the 3 nutrients differed significantly at p<0.05. Weight gain (WG) (g) was highest (17189.33 ± 506.61g) in fish fed diet A (Coppens feed), followed by 15045.33±202.42 g (diet B) (SBD) and least (14357.33 ± 108.25 g) (diet C) (COBD). The Growth rate (GR) was highest in fish fed with diet A (111.62 ± 3.29 g/day), followed by 97.69±1.31 g/day (diet B), and least (93.23±0.70 g/day) in diet C. Specific growth rate (SGR) was highest in juveniles fed diet A (2.02 ± 0.02 %/day), followed by 1.94±0.01 %/day for diet B, and least (1.91±0.01 %/day) for diet C. Mean growth rate (MGR) was highest in juveniles fed diet A (11.88 ± 0.29 mg/day), followed by 11.74±0.15 mg/day for diet B, and least (11.69±0.09 mg/day) in fish fed diet C. The WG, GR and SGR varied significantly between the juvenile fish group fed the 3 diets at p<0.05, while MGR did not vary significantly between fish group fed the 3 diets at p>0.05. Fish fed diet A had a higher feed consumption (FC) (41650.00 ± 315.34 g/kg), than that fed diet B (39034.24 ± 86.34 g/kg) and then diet C (38276.00 ± 342.97 g/kg). Juveniles fed Coppens feed did better, with a feed conversion ratio (FCR) of 2.42 ± 0.06, followed by 2.59±0.04 for diet B and 2.67 ± 0.03 for fish fed diet C. Feed conversion efficiency (FCE) was higher in fish fed diet A (41.26±0.94 %), followed by 38.54 ± 0.54 % (diet B) and least (37.52 ± 0.51 %) (diet C). The FC and FCR varied significantly between the fish fed the 3 diets at p<0.05, while FCE was not significantly different between the 3 treatment groups at p>0.05. The water parameters of the culture water varied significantly between each treatment groups (p<0.05), and were within the rage suitable for normal growth of fish. Though coppens feed yielded better growth performance and feed utilisation, the use of COBD and SBD is recommended for fish farmers in Nigeria. More researches should be carried out on using chicken offals and shrimps in fish feed formulation.

Salt stress is one of the main factors limiting plant growth and yield globally. Seed priming technique with different chemicals including β-aminobutyric acid (BABA) is found to be effective in enhancing plant growth and development under biotic and abiotic stresses. Scarce reports have been found about BABA seed priming in medicinal plants under stress conditions; however, several studies have been conducted on other crops but have not made an in-depth study to investigate biochemical and physiological changes. In current study the shoot growth, relative water content (RWC), chlorophyll content, stomatal conductance, nutrient content (N, P, K, Na and Cl), proline, malondialdehyde (MDA), hydrogen peroxide (H₂O₂) content, antioxidants enzymes (CAT, SOD and POD), membrane stability index (MSI), total phenolic and flavonoids contents lipid peroxidation and membrane permeability were investigated in Calendula officinalis L. leaves due to BABA seed priming and/or salt stress treatment. Salt stress treatment significantly reduced the growth characters, inflorescence number as well as its fresh and dry weights, N, P and K contents in leaves, RWC, chlorophyll content, stomatal conductance, MSI and total phenolic and flavonoids contents of pot marigold. However, proline content, MDA accumulation, H₂O₂ content and antioxidant enzyme activity (CAT, SOD and POD) were increased due to salt stress. On the other hand, seed priming with BABA significantly improved the growth characters, inflorescence attributes and the previously mentioned physiological and biochemical parameters investigated relative to the control. Applying seed priming under salt stress conditions significantly mitigated the negative effects of salinity and enhanced the growth and productivity of pot marigold and therefore was suggested to be an effective technique prior to cultivation.

The use of extracellular or circulating nucleic acids (Cfs), as a diagnostic or prognostic tool in oncology, has been broadly documented. However, their use in gynecology-obstetrics as non-invasive biomarkers in the management of infertility has become a recurring fact. The circulating nucleic acids are constituted by: free DNA which can be long or short DNA strands resulting from the apoptotic or necrotic processes, the free RNA containing: micro-RNAs (miRNAs) which are short single-stranded ribonucleic acids (RNA) that are able to deter the production of  protein from a gene, Piwi-interacting RNAs (PiRNAs) that are small RNAs expressed in germ cells or even early embryos and small interfering RNAs (siRNAs) that are small RNAs that can bind specifically to a messenger RNA sequence and prevent gene expression by cleaving that RNA. The presence of circulating nucleic acids in many biological fluids such as: urine, seminal plasma and serum, the fact that they are easy to detect, the variation of their level according to the physiopathological conditions of the body and their implication in many biological processes such as folliculogenesis, steroidogenesis and spermatogenesis make nucleic acids circulating important biomarkers of interest in the management of male infertility. They compose a real complementary help for practitioners of medically assisted procreation. As a result, circulating nucleic acids are a promising avenue in the prevention of implantation failures. In this article, we will seek to affirm further, their importance in the management of male infertility, by highlighting their different uses.