Development of a defined mixed starter culture for the improvement of Tej, Ethiopian honey wine.

Ethiopian honey wine, Tej, is the most popular traditionally fermented alcoholic beverage in Ethiopia. Owing to the spontaneous fermentation process, the final product is neither predictable nor consistent in quality. Attempts have not been made before to solve this problem. Thus, the aim of this study was to develop a potential mixed starter culture of yeast and lactic acid bacteria isolated from Tej samples for the production of Tej with consistent quality. One hundred seventy-seven lactic acid bacteria and 194 yeasts were isolated from 30 Tej samples collected from southwest Ethiopia. After sequentially testing the isolates towards physiological stress tolerance and desired metabolic products, 10 lactic acid bacteria and 10 yeast isolates were screened. Later, four lactic acid bacteria and four yeast isolates were found to be compatible in co-culture tests. Finally, the combination of lactic acid bacteria and yeast isolates was formulated using the design of expert version 7.0.0 software, and six formulates (F #1-6) were designed. Controlled Tej fermentation was performed under laboratory conditions using six lactic acid bacteria-yeast starter culture formulations. The sensory attributes, in terms of color, flavor, odor, turbidity, and overall acceptance analysis scored 4.8/5.0 (F #2) and 4.7/5.0 (F #6), with mean significant variations (p < 0.05) among the other formulates. These two formulates were considered the best-mixed starter cultures compared to the control and other formulates. Matrix-assisted laser desorption ionization-time of flight analysis revealed that the lactic acid bacteria starters (AAUL7 and AAUL10) belonged to Lactobacillus paracasei. While the yeast starters (AAUY2 and AAUY8) belonged to Saccharomyces cerevisiae. These mixed lactic acid bacteria-yeast starter cultures could be used as the best starter culture for the fermentation of Ethiopian honey wine, Tej, with consistent quality.

Comparative analysis of the physicochemical, proximate, and antioxidant characteristics of stingless bee (Meliponula beccarii) honey from modern and wild beehives in Ethiopia.

There is a dearth of information on the comparative studies of the physicochemical, proximate, and antioxidant properties as well as quality standards of stingless bee honey (SBH) in Ethiopia. Hence, this study was designed to assess and compare the physicochemical, proximate, and antioxidant properties of SBH, specifically sourced from Meliponula beccarii, and produced under both wild and modern apiary conditions at two distinct geographical locations. A total of forty-six honey samples were meticulously collected from domesticated stingless bee colonies and naturally occurring wild nests at Wolmera and Cheliya districts. Pollen analysis unveiled eleven distinct bee plant species distributed across six families, with Asteraceae being the most prevalent, primarily represented by Guizotia scabra and Vernonia amygdalina. Notably, the physicochemical, proximate, and antioxidant properties of SBH collected from modern pot hives exhibited significant variances (p < .05) when compared to SBH from wild nests. Principal component analysis (PCA) delineated the differentiation of SBH sources based on both geographical location and the type of beehive. One-way ANOVA corroborated these distinctions, underscoring significantly higher levels (p < .05) of ash, electrical conductivity, free acidity, hydroxymethylfurfural, sucrose, total phenolic content, total flavonoid content, and radical scavenging activities of SBH from modern pot hives in Wolmera. Whereas, Cheliya modern pot hives recorded higher values in pH, hydroxymethylfurfural and maltose contents compared to the wild nest SBH. Further analysis through Pearson correlation highlighted a strong positive association between total phenolic content and total flavonoid content with the antioxidant capacity of SBH. These findings underscore the significance of integrating modern pot hives to enhance the quality of SBH within Ethiopia's beekeeping sector.

Microbial, physicochemical and proximate analysis of Tej collected from Amhara regional state of Ethiopia.

Tej is an Ethiopian traditional alcoholic beverage with significant social and economic importance. Due to the spontaneous fermentation process of Tej, several issues such as safety, quality, and physicochemical properties of the final products is rquired to be assessed. Thus, this study was aimed to assess the microbial quality, physicochemical, and proximate properties of Tej associated with different maturity time. The microbial, physicochemical and proximate analyses were carried out by standard protocol. Lactic acid bacteria (6.30 log CFU/mL) and yeast (6.22 log CFU/mL) were the dominat microorganisms of all Tej samples at different maturity time, with significant differences (p = 0.001) in mean microbial count among samples. The mean pH, titratable acidity and ethanol content of Tej samples were 3.51, 0.79 and 11.04% (v/v), respectively. There were significant differences (p = 0.001) among the mean pH and titratable acidity values. The mean proximate compositions (%) of Tej samples were as follows: moisture (91.88), ash (0.65), protein (1.38), fat (0.47) and carbohydrate (3.91). Statistically significant differences (p = 0.001) were observed in proximate compositions of Tej samples from different maturity time. Generally, Tej maturity time has a great impact on the improvement of nutrient composition and the increment of the acidic contents which in turn suppress the growth of unwanted microorganisms. Further evaluation of the biological, and chemical safety and development of yeast-LAB starter culture are strongly recommended to improve Tej fermentation in Ethiopia.

Knowledge, attitudes and practices on household solid waste management and associated factors in Gelemso town, Ethiopia.

Improper solid waste management in urban and semi-urban cities of developing countries is the source of environmental pollution and public health concern. This study aimed to assess the households' knowledge, attitudes and practices of solid waste management and associated factors in Gelemso town. A community-based cross-sectional study design was used to assess the households' KAP of SWM in Gelemso town. A systematic random sampling technique was used to recruit 390 households from Gelemso town and data was collected using a structured questionnaire. Data analysis was carried out using SPSS version 22.0 software. Bivariate and multivariate analyses were used to predict the improper SWM practices. From 390 households included in the study, 61.3% of them were females. Generally, most households had correct knowledge and positive attitudes towards SWM but poor practice was observed in the study area. About 96% of the households considered solid waste as a source of environmental pollution and close to 92% of them replied that solid waste can be used for compost preparation. Majority (87.4%) of the households "strongly agreed" about the potential risk associated with improper solid waste disposal and nearly 80% of them also "strongly agreed" that proper SWM is crucial to create a healthy environment in the community. Nearly 80% had practiced improper SWM. Logistic regression analyses indicated that lack of experience in sorting solid waste, ways of removal, knowledge about reduce, reuse and recycle, absence of adequate solid waste landfills, and lack of door-to-door waste collections services were identified as the major contributing factors for the improper SWM practice in Gelemso town. In conclusion, the majority of the households had practiced improper SWM, such as disposing of solid waste in the backyard, along the roadsides, in gully and burned. These malpractices can significantly affect the environment and public health of the residents.

Seasonal Profile and Five-Year Trend Analysis of Malaria Prevalence in Maygaba Health Center, Welkait District, Northwest Ethiopia.

BACKGROUND: Malaria is a serious public health problem of most developing countries, including Ethiopia. The burden of malaria is severely affecting the economy and lives of people, particularly among the productive ages of rural society. Thus, this study was targeted to analyze the past five-year retrospective malaria data among the rural setting of Maygaba town, Welkait district, northwest Ethiopia. METHODS: The study was done on 36,219 outpatients attending for malaria diagnosis during January 2015 to 2019. Data was extracted from the outpatient medical database. Chi-square (χ 2) test and binary logistic regression model were used to analyze the retrospective data. Statistical significance was defined at p < 0.05. RESULTS: Of 36,219 outpatients examined, 7,309 (20.2%) malaria-positive cases were reported during 2015-2019. There was a fluctuating trend in the number of malaria-suspected and -confirmed cases in each year. Male slide-confirmed (61.4%, N = 4,485) were significantly higher than females (38.6%, N = 2,824) (p < 005). Plasmodium falciparum and Plasmodium vivax were the dominant parasites detected, which accounted for 66.1%; N = 4832, 33.9%; N = 2477, respectively. Despite the seasonal abundance of malaria cases, the highest prevalence was recorded in autumn (September to November) in the study area. Binary logistic regression analysis revealed that statistically significant associations were observed between sexes, interseasons, mean seasonal rainfall, and mean seasonal temperature with the prevalence of P. vivax. However, P. falciparum has shown a significant association with interseasons and mean seasonal temperature. CONCLUSIONS: Although the overall prevalence of malaria was continually declined from 2015-2019, malaria remains the major public health problem in the study area. The severe species of P. falciparum was found to be the dominant parasite reported in the study area. A collaborative action between the national malaria control program and its partners towards the transmission, prevention, and control of the two deadly species is highly recommended.

Prevalence of Gonorrhea and Associated Knowledge, Attitude and Risky Behaviors and Preventive Practices Among High School Students: A Cross-Sectional Study.

Gonorrhea is a curable sexually transmitted infection that affects the health of people globally. Millions of new gonorrhea cases are reported every year in people aged 15 to 49 years. Particularly adolescents are vulnerable due to high sexual desire and unsafe sexual practices. The aim of the study was to determine the prevalence of gonorrhea and the associated knowledge, attitude and risky behaviors and preventive practice of high school students in Addis Ababa, Ethiopia. A cross-sectional study was conducted among 410 students from grade 11 and 12 of Medhane-alem preparatory school using self-administered questionnaires. Statistical analysis was carried out using SPSS version 22.0 software. Chi-square test and odds ratio were done at 95% CI using significance level of p < 0.05. The prevalence of gonorrhea among the students was 5.4%. Only 40% of participants were knowledgeable on gonorrhea transmission and less than 50% of them had positive perception towards gonorrhea infected people. Over 55% of the students had no sexual history but the rest had previous sexual experience and were exposed, at least, to one risky behavior. Logistic regression analysis revealed that higher acceptable sexual practice was observed among students with good knowledge than students with poor knowledge (AOR = 2.12, 95% CI 1.42-3.18, p < 0.001). Overall, higher prevalence rate and low knowledge level was observed among the study group. Negative attitudes and unsafe sexual practices were reported by the students. Sexual health education and prevention are necessary among the high school students.

A highly active pantothenate synthetase from Corynebacterium glutamicum enables the production of D-pantothenic acid with high productivity.

D-Pantothenic acid (vitamin B5) has wide applications in the feed, food, chemical, and pharmaceutical industries. Its biological production routes which employ pantothenate synthetase (PS) as the key enzyme are attractive since they avoid the tedious and time-consuming optical resolution process. However, little data is available on the activity and kinetics of this enzyme, hampering the rational selection of an efficient enzyme for the biological production of D-pantothenic acid. In this study, six phylogenetically distant PS-encoding genes, from Escherichia coli, Corynebacterium glutamicum, Bacillus subtilis, Bacillus thuringiensis, Bacillus cereus, and Enterobacter cloacae, were expressed in E. coli. The PS from C. glutamicum exhibited a specific activity of 205.1 U/mg and a turnover number of 127.6 s-1, which to our best knowledge are the highest values ever reported. The addition of substrates (D-pantoic acid and ß-alanine) to the E. coli strain harboring this enzyme during the early log phase of fermentation resulted in the production of 97.1 g/L of D-pantothenic acid within 32 h, corresponding to a conversion yield of 99.1% and a productivity of 3.0 g/L/h. To the best of our knowledge, this is the highest productivity reported to date.

Molecular engineering of L-aspartate-α-decarboxylase for improved activity and catalytic stability.

ß-Alanine is an important precursor for the production of food additives, pharmaceuticals, and nitrogen-containing chemicals. Compared with the conventional chemical routes for ß-alanine production, the biocatalytic routes using L-aspartate-α-decarboxylase (ADC) are more attractive when energy and environment are concerned. However, ADC's poorly understood properties and its inherent mechanism-based inactivation significantly limited the application of this enzyme. In this study, three genes encoding the ADC enzymes from Escherichia coli, Corynebacterium glutamicum, and Bacillus subtilis were overexpressed in E. coli. Their properties including specific activity, thermostability, and mechanism-based inactivation were characterized. The ADC enzyme from B. subtilis, which had higher specific activity and thermostability than the others, was selected for further study. In order to improve its activity and relieve its mechanism-based inactivation by molecular engineering so as to improve its catalytic stability, a high-throughput fluorometric assay of ß-alanine was developed. From a library of 4000 mutated enzymes, two variants with 18-22% higher specific activity and 29-64% higher catalytic stability were obtained. The best variant showed 50% higher ß-alanine production than the wild type after 8 h of conversion of L-aspartate, showing great potential for industrial biocatalytic production of ß-alanine.