This study has been embarked upon due to increased resistance of bacteria to many already synthesized drugs and the high price of the orthodox medicines in the market, the antimicrobial effect of Psidium guajava leaf extracts against selected drug-resistant bacteria will help to reduce the overdependence on orthodox or synthetic drugs which greater population of the society cannot afford due to economic/financial restriction. Ethanolic and aqueous extracts of Psidium guajava were assayed for antibacterial activity using the agar dilution method in the determination of the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC). The bioactive components of the extracts were determined using standard techniques and the inhibitory activities of the extracts were compared to gentamicin, ciprofloxacin, erythromycin, azithromycin, ofloxacin, and nitrofurantoin. The MIC of the extract on the test organisms ranges from 10 mg/ml -40 mg/ml. The sensitivity test showed that the organisms were susceptible to Psidium guajava leave extract except Pseudomonas aeruginosa. The phytochemical analysis of the extracts revealed the presence of bioactive compounds such as Tannin, Saponin, Balsam, Flavonoids, Alkaloids, Cardiac glycosides, Carbohydrate, Resins, Terpenes, and Sterols. It has been shown that the leaves of Psidium guajava have antibacterial effects and hence can be used to treat the ailments caused by those organisms at a particular dosage and concentration. However, more research work on its toxicity level, synergistic or antagonistic interaction with other plants or drugs is needed to consolidate its usage.

Human vitamin deficiencies still occur in many countries although most vitamins are present in a variety of foods, mainly because of malnutrition not only as a result of insufficient food intake but also because of unbalanced diets; this work screens some Lactic acid bacteria isolated from selected Nigerian fermented foods for vitamin (thiamine, riboflavin and niacin) production. Five lactic acid bacteria were isolated from selected Nigerian fermented foods (yoghurt, ogi, ogiri, ugba). The isolated lactic acid bacteria were identified based on cultural and biochemical characteristics. All the isolates were screened for thiamine, riboflavin and niacin production using microbiological assay. Thiamine, riboflavin and niacin produced were quantified.

In the quest to produce an acceptable local beverage that could serve as an alternative variety to kunun-zaki for many millions of Nigerians who take the cereal-based beverage as their most preferred and affordable drink a study was undertaken to assess the microbial and sensory quality attributes of laboratory-produced Date fruit-based kunun-zaki. Different blends of dry date fruits (Phoenix dactylifera) and sorghum (Sorghum bicolor) formulated as follows; F1 (100:0), F2 (70:30), F3 (50:50), and F4 (30:70%) of date fruits/sorghum were soaked overnight in water, drained and were wet-milled with ginger and cloves using an equal volume of sterile water, F5 (0:100) was market (Control) sample. The microbial succession study included the identification of organisms at various critical stages of the production of the beverage. The results of the study showed the mean pH, and TTA (%) values for the respective formulated Kunun-dabino product were F1 (4.87 and 0.3870), F2 (4.66 and 0.4508), F3 (4.29 and 0.4600), F4 (4.04 and 0.4690), F5/Control (4.32 and 0.4589) respectively. The mean Total bacterial, coliform and fungal loads of the four experimental products were 2.58 x 104, NIL, and 3.56 x 103 CFU/ml respectively which fall within W.H.O’s recommended standards for ready-to-eat foods. Species of Bacillus, Enterobacter, Shigella, Lactobacillus, Aspergillus, Penicillium Mucur, and Candida were present at the initial production stage while Bacillus and Lactobacillus species persisted right through to the final stage of production. The results of the sensory evaluation showed that while F1 was the least liked, F3 was significantly preferred over the other samples (P < 0.05). The study has shown that ‘Kunun dabino’ produced under the laboratory conditions in this study provides a new brand of beverage that is both microbiologically safe and organoleptically more acceptable to taste panelists.

For production and preservation of traditional fermented foods, the genera, lactic acid bacteria (LAB) have been used. This study was carried out to determine the characteristics and the antimicrobial activities of lactic acid bacteria isolated from selected Nigerian traditional fermented foods. Changes in pH and titratable acidity (TA) of the samples were investigated for a period of four days (96 h). Eleven tentative LAB from fermented maize and cassava (Ogi and Fufu, respectively) were isolated and characterized. The spoilage organisms from fish were aseptically identified and the antimicrobial activity was determined by agar well diffusion method against three isolated food spoilage organisms (Pseudomonas aeruginosa, Enterobacter aerogene and Bacillus cereus). The isolates were selected and further identified as Lactobacillus amylolyticus strain L6, Lactobacillus plantarum strain ci-4w and Lactobacillus sakei strain MLS1 by the aide of genotypic characteristics (16S rRNA gene sequences). These strains were screened for their EPS producing activity, resistance to low pH and bile salts as well as bacteriocin activity. These strains can be used as starter culture or protective cultures to improve the hygiene, quality and increased safety of the food products by inhibiting the food borne pathogens and spoilage microorganisms.

Pseudomonas aeruginosa is a major pathogen in humans and other animals, frequently harboring mechanisms of resistance to commonly used antimicrobials. Here, we describe the isolation of P. aeruginosa bacteriophage Zikora. The full 65,837-bp genome was annotated and demonstrates similarity to Pbunavirus phages, making Zikora a new member of this genus of the Myoviridae family.

No abstract

Potato (Solanum tuberosum) cultivation was introduced into Nigeria in the Jos Plateau in the early 20th century (Zemba et al., 2013) The Jos Plateau is at high altitude, c. 1,200 m above sea level, and has a cool climate favourable for the crop. Nigeria is the fourth biggest producer of potato in sub-Saharan Africa with a production of about 843,000 tonnes per year and the Jos South Local Government Area accounts for 25% of the total production in Nigeria.

Among the potential benefits of probiotic lactic acid bacteria (LAB) is their practical use for biopreservation of foods, fungal decontamination, and novel biotherapy. A number of ready to eat foods hawked in streets of Nigeria such as garri are prone to contamination by mycotoxin-producing fungi. In this study the inhibitory effect of lactic acid bacteria (LAB) (sourced from local foods (nono and kunun- zaki)) and their bacteriocins-derivatives on aflatoxin B1 -producing Aspergelius flavus was conducted. Out of the five LAB isolates screened three (two strains of Lactococcus and one of Pediococcus sp had high indices of probiotic potentials and bacteriocins extracts were obtained from them and used for the inhibition study. Fourty samples of garri sold in Jos metropolis were screened for A. flavus and their abilities to produce Aflatoxin B1 using the Coconut Extract Agar (CEA) and Ammonia Vapour Test (AVP) methods. The three most probiotic LAB and their respective crude baterioncin extracts were used to test for their inhibitory effect on aflatoxin producing A. flavus isolates. The results of the study showed that while only 17 samples (42.50%) had A. flavus in them, only three of the fungi ((17.65%) demonstrated capacity to produce Aflatoxin B1, making (7.5% of the total number of garri samples that had aflatoxin-producing A. flavus. The inhibition of fungal growth by LAB and bacteriocins was dose dependent. At an inoculum concentration of 1 ml, Pediococcus sp had the highest mean zone of inhibition of 43.0 mm followed by Lactococcus sp (Strain LAC20G with radial diameter 38.0mm and Lactococcus sp (LAC20G) which had a radial diameter of 29.3mm respectively. The results of the study portend that the growth of aflatoxin producing Aspergillus flavus in ready to eat foods such as garri could be prevented by application of appropriate dosages of bacteriocins extracts from lactic acid bacteria.