Constructional features of a 15-litre home-made bioreactor for fed-batch fermentations

A 15-litre bench-top multipurpose bioreactor was designed and constructed. The vessel is a glass type with a stainless flat headplate incorporating 9 access ports allowing for a variety of interchangeable probes and actuators. The stirring speed ranges between 0 and 250 rpm, the aeration rate (0-2 l/m), the pH control loop uses HI 1131 probe, two 100 ml bottles of HCl and NaOH solutions and operates a close feedback system. The temperature control module is a close loop using a PT 100 RTD   thermocouple and an auxiliary vessel containing a cooling solution. The aeration and feed flow rates are open loops. The system incorporates attributes of a good bioreactor design as discussed by Naraendranathan (1998). Sterility is achieved by autoclaving different units of the system. This machine has been tested on an array of local standard fermentation processes. (African Journal of Biotechnology: 2003 2(8): 233-236

A call: COVID-19 research funding in Africa

French Title: Un appel: le financement de la recherche COVID-19 en Afriqu

Mycomeat Production through the Solid State Fermentation of Soymilk Waste by Lentinus Subnudus

Lentinus subnudus was cultured on soy milk waste with the view of using it to produce edible mycomeat. The solid state fermentation of soymilk waste was done singly without any additive. The basal substrate was then variously constituted with 5 g/l each of sucrose, citric acid and yeast extract. The set-ups were incubated in the dark and monitored daily until full ramification was obtained. The best mycomeat obtained within the shortest time frame was oven dried at 600C and then blended to powder. The pH, proximate and mineral composition of the mycomeat was determined. L. subnudus grown on soymilk wastes took only 11 days in which the resultant mycomeat of L. subnudus was found to be meaty-like in appearance and aroma. Oven-dried samples became coarse in texture with a pH of 3.91. Proximate analysis of the mycomeat showed 2.13% moisture content, 14.44% crude protein, 51.8% carbohydrate 9.56% crude fibre, 15.82% ether extract and 5.75% ash content. The percentage mineral composition revealed it to contain; Ca2+ (0.62±0.02), Mg2+ (0.03±0.01), K+ (0.06±0.01) Na+ (15.90±0.30), Mn2+ (8.20±0.04), Fe 2+ (19.22±0.21), CU2+ (2.74±0.02) , Zn2+ (7.17±0.01) Mo2+ (0.05±0.01) and Vitamin C (0.24±0.01). The resultant mycomeat represents a viable source of nutraceuticals . Keywords: Mycomeat, Lentinus subnudus, soymilk waste, mineral composition, proximate analysis

Ameliorative effect of Lentinus squarrosulus mycomeat against Pseudomonas aeruginosa infection using albino rat as animal model

The increasing awareness of inherent therapeutic and prophylactic benefits of some higher fungi and their products has been the recent trend for improving a healthy vigour. Mycomeat is a mushroom derived ‘meat-like’ product produced using solid state fermentation technique. Previous research in this group revealed mycomeat as a potentially useful neutraceutical. This study seeks to explore the potential of mycomeat as a therapeutic agent against Pseudomonas aeruginosa infections. Three concentrations (83.3, 166.6 and 250 mg/kg body weight) of powdered mycomeat were prepared and administered to P. aeruginosa infected wistar rats. Morphological appearance and behavior of the rats were used as the assessment method for adverse reactions. After a period of 26 days, the rats were sacrificed with the liver, spleen and testes aseptically excised for histopathological analysis, the sperm count and sperm motility assay was carried out. Histopathological analysis revealed the testis of therapeutic group administered with 83.3 mg/kg as having a normal seminiferous tubule, while other organs were adversely affected. The group administered with 166 mg/kg of mycomeat has a normal hepatocyte, normal seminiferous tubule and splenic cells. Results from the therapeutic group were consistently better than the prophylactic group. The untreated group showed anomaly in the three organs inspected. The sperm count but not motility was significantly higher in the treated group than that observed in the positive and negative control group. This study was able to establish that mycomeat could be used to preserve body organs, at a dose of 166 mg/kg body weight. It can also be used as a birth control neutracetical for males.Keywords: Mushroom, Lentinus subnudus, histopathology, birth control, fertilit

Preparation of Oligosaccharide using Amylase enzyme isolated from soil at cassava dump sites in Ogbomoso, Oyo State, Nigeria

No Abstrac

Haemagglutination assay of some human and animal arcobacter specie

Arcobacter are emerging food borne enteropathogens which can cause severe diarrhea and occasional systemic infection such as bacteraemia and peritonitis in humans. To understand the pathogenicity of this emerging pathogen, putative adhesive factors in the organism were studied by examining their ability to agglutinate erythrocytes from humans and other animal species. A total of 10 Arcobacter species from which four strains were obtained from humans and one from pigs in France. Five isolates were obtained from stool of healthy pigs and chicken in Nigeria. They were identified and confirmed by phenotypic and PCR techniques. Bacteria cells were washed in PBS by centrifugation. 20 μl of bacteria cells was reacted with equal volume of erythrocytes. Macroscopic haemagglutination was scored as either positive or negative after 5 minutes of mixing at room temperature. To understand the nature of red cell receptor for haemagglutinin, various sugars was used to inhibit previously positive haemagglutination reaction. Fresh cultures of all strains agglutinated erythrocytes from humans (blood group A+), sheep, guinea-pig and chicken. 20μl of all suspension containing 10 cells\ml gave a strong microscopic haemagglutination within 5 minutes after mixing with an equal volume of 3% erythrocytes suspension on a clean microscopic slide. No inhibition was observed with D glucose and mannose on previously positive haemagglutinating strains, but galactose inhibited by the same 50/50% (v|v). The result of this experiment provides a basis for further development of specific immunogen required for a more detailed study of characterization of specific adhesins.Keywords: Arcobacter, Haemagglutination, Adhesive factors, Nigeri