Utilization of local agro-industrial by-products based substrates to enhance production and dietary value of mushroom (P. ostreatus) in Ethiopia.

Food insecurity and malnutrition are serious problems in many developing countries, including Ethiopia. This situation warrants an urgent need for the diversification of food sources with enhanced productivity. This study was aimed at contributing to the food security in Ethiopia through cultivation of Pleurotus ostreatus mushrooms using sustainable and locally available agro-industrial byproduct-based substrates in parallel with pollution control. Ten substrates were prepared using sugarcane bagasse, filter cake, trash, cotton seed hull and animal waste, namely cow dung and horse and chicken manure. The effect of each substrate (treatment) on the yields, biological efficiency, nutritional composition, and mineral contents of Pleurotus ostreatus mushroom species was evaluated at the Ethiopian Forest Products Innovation Center, Addis Ababa, Ethiopia. The results obtained indicate that a significantly higher (p < 0.05) yield and biological efficiency were recorded from the mushroom cultivated on S2 substrate containing a mixture of 80% sugarcane bagasse, 12% cow dung, and 8% cotton seed hull. Moreover, substrate containing sugarcane bagasse mixed with cotton seed hull, cow dung, and chicken manure significantly (p < 0.05) increased the yields and biological efficiency of the mushroom. The content of protein, crude fat, fiber, and carbohydrates of the mushroom cultivated from all the utilized substrates were in the range of 17.30-21.5, 1.77-2.52, 31.03-34.38, and 28.02-39.74%, respectively. The critical macro-elements are abundant in the mushroom in the order of potassium, magnesium, calcium, and sodium. The mushrooms cultivated on all the substrates were rich in essential micro-elements in the order of iron and zinc. It was found that substrate preparation and formulation significantly (p < 0.05) improved the yields, biological efficiency, nutritive values, and mineral contents of the mushroom. The use of these by-products as substrates is sustainable and environmentally friendly and allows the production of mushroom with high nutritional value on a sustainable basis in order to enhance food security in the country.

Melissopalynological analysis and microbiological safety of fresh and market honey (Apis mellifera L. and Meliponulabeccarii L.) from Western Oromia, Ethiopia.

Honey is a natural product that is made by bees from the nectar of flowering plants. There is a flora preference by bees. Like other foods ready to eat,honey can be prone to microbial contamination. Honey plant sources can be analyzed from the composition of pollen grains in honey samples. The objective of this study was to assess microbial safety and floral origin of the honey samples. For this study, honey samples were purchased from local market, and collected from hives (fresh honey) in Western Oromia. Floral analysis was determined using harmonized method of melissopalynology. Microbiological safety was assessed through the pour plate procedures from the first serial dilution on a total of 45 honey sample sizes.The melissopalynological analysis demonstrated that A. melliferahoney purchased from the market(AMMH) was considered a multi-floral type while A. mellifera fresh honey (AMFH) cropped directly from the hive and M.beccarii honey purchased from the market (MBMH) was dominated pollen from Coffee arabica (68 % of its pollen grain counted) and Guizotiascabra (50.53 % of its pollen grain counted) plant, respectively. The Aerobic mesophilic bacteria, Staphylococci, Yeast, Mould, and Aerobic spore-forming bacteria were found below the standard countable level (<30 cfu/plate) from A. mellifera and M.beccarii honey bought from the market, while A. mellifera honey collected directly from the hive became free of any microbial contamination. C.arabica and G.scabra are major honey plants and their honey can be harvested in February and October, respectively. Furthermore, Vernoniaamygdalina, Eucalyptus spp, Combretummolle, Trifoliumruppelianum, and Syzgiumguineense were honey plants analyzed from multifloral market honey even though, their pollen dominance varies. M. beccarii visits herbaceous flora whilst A. mellifera visits all floral types. The level of contamination of the honey samples from the study area was very low showing its safety.

Substrate Optimization for Shiitake (Lentinula edodes (Berk.) Pegler) Mushroom Production in Ethiopia.

Edible mushrooms are seen as a way of increasing dietary diversity and achieving food security in Ethiopia. The aim of this study was to develop substrates using locally available agro-industrial by-products and animal manures to enhance the production of Shiitake (Lentinula edodes) mushrooms in Ethiopia. The hypothesis was L. edodes mushroom production on seven different substrates: 100% sugarcane bagasse (S1), 80% sugarcane bagasse, 20% cow dung (S2), horse manure (S3), chicken manure (S4), cottonseed hulls (S5), sugarcane filter cake (S6), and sugarcane trash (S7). Mushroom yield and biological efficiency were significantly affected by substrate type (p < 0.05). A significantly higher yield (434.33 g/500 g of substrate) and biological efficiency (86.83%) were obtained using substrate S4 while lower yield (120.33 g/500 g) and biological efficiency (24.33%) were obtained using substrate S7 than when using other substrates. The largest first flush of mushrooms was obtained on S4, and five flushes were produced on this substrate. S4 also had the highest biological efficiency, the highest nitrogen content, and the lowest C:N. Chicken manure is rich in nitrogen, magnesium, calcium, and potassium, which are crucial for Shiitake mushroom growth. Thus, substrate S4 would be a viable option for cultivating Shiitake mushrooms, particularly in regions where chicken manure is readily available. Substrate S2 also provided high yields and rapid fructification and would be a suitable alternative for Shiitake mushroom cultivation.

Purification and Characterization of Bioactive Metabolite from Streptomyces monomycini RVE129 Derived from the Rift Valley Soil of Hawassa, Ethiopia.

Streptomyces species have produced a variety of bioactive secondary metabolites with intriguing antimicrobial and anticancer properties. In this study, the bioactive compound obtained from the potent strain RVE129 was purified and characterized. Its bioactivity against various pathogens and its cytotoxicity toward the human cervical cancer (HeLa) cell were also examined. The strain was previously isolated from unexplored areas of the rift valley soil of Hawassa (Ethiopia) and identified by phenotypic characteristics and complete sequencing of the 16S rRNA gene and found to be closely related to Streptomyces monomycini strain NRRL B-24309 (99.65%); accession no. (ON786620). The active fraction undergoes bioassay-guided purification using the TLC method after being extracted by ethyl acetate. Then, it was subjected to physicochemical and structural characteristics using UV-Vis, FTIR, and NMR spectroscopic methods. A minimum inhibitory concentration of the purified antibiotic was achieved by the broth microdilution method. The cytotoxicity of HeLa cells was determined using the 3-(4,5-dimethylthiazole-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. The acquired data from spectroscopic studies was compared with that of the reported natural compounds in data bases and found to be the known antibiotic, setamycin. The antibiotic (RVE-02) showed a broad spectrum of bioactivity against both Gram-positive and Gram-negative bacteria, with MIC values that ranged from 1.97 to 125 µg/ml. The bioactivity results also demonstrated antiproliferation and morphological change in HeLa cells with an IC50 value of 24.30µg/ml of antibiotic. The antibiotic, obtained from S. monomycini RVE129, could be a potential candidate to combat pathogens including drug-resistant S. aureus. Further, the effect on HeLa cells suggests that it could be a prominent cancer chemotherapeutic agent.

Antimicrobial Potential of Streptomyces spp. Isolated from the Rift Valley Regions of Ethiopia.

The study was undertaken to isolate, screen, and identify actinomycetes with antimicrobial metabolites. Twenty-one composite soil samples were randomly collected from various unique agroecological niches in the Rift Valley of Ethiopia. The soil samples were serially diluted and spread on starch casein agar medium supplemented with 50 µg/ml cycloheximide and 25 µg/ml nalidixic acid. Two hundred and forty-nine (249) actinomycetes cultures were isolated and screened by cross streaking against various human pathogens. Twenty-four isolates with pronounced antimicrobial activity were selected for identification and further screening. Among the isolates, 172 (69.1%) showed antimicrobial activities against tested pathogens. The inhibition zone of the isolates ranged from 5 ± 0.31 to >40 mm during primary screening. The antimicrobial activity of the crude extracts of promising isolates showed a statistically significant difference (P < 0.05) between them and the control. The isolates RVE129 and RVE217 showed the maximum zone of inhibition at 27 ± 0.6 mm and 26 ± 0.6 mm, respectively, against S. aureus, and the results were higher than the standard drug streptomycin (25 ± 0.58 mm). The inhibition zone of crude extracts from RVE129 was at the maximum of 22 ± 0.0 mm against P. aeruginosa, almost comparable to the standard drug streptomycin (24 ± 0.58 mm). Crude extract from the isolates RVE129 and RVE187 showed higher inhibition zones of 22 ± 0.6 mm and 16 ± 0.33 mm against A. niger ATCC10535, which, however, were smaller than those obtained with the standard drug amphotericin B (29 ± 0.6 mm). Twenty-four actinomycete strains with remarkable bioactivity were characterized using various cultural, morphological, physiological, and biochemical characteristics and assigned under the genus Streptomycetes. The finding of the current study indicates that Streptomyces sp. isolated from the Rift Valley of Ethiopia was found to possess a broad spectrum of bioactivity against a range of human pathogens.

Biocontrol competence of Beauveria bassiana, Metarhizium anisopliae and Bacillus thuringiensis against tomato leaf miner, Tuta absoluta Meyrick 1917 under greenhouse and field conditions.

Tomato is one of the most important crops grown under both greenhouse and field conditions throughout the world. Its production is highly challenged by infestation of leaf miner insect, Tuta absoluta Meyrick regardless of excessive insecticide application. The chemical insecticides results insect resistance, environmental pollution, and health problems and there is urgent need for management options such as integrated pest management (IPM) to obviate these problems. Thus, the present study aims to evaluate the effectiveness of single and combination treatments of entomopathogens; Beauveria bassiana, Metarhizium anisopliae, Bacillus thuringeinsis, and an insecticide against T. absoluta under greenhouse and field conditions. Two varieties (Awash and Venes) of tomato for greenhouse experiment and one (Gellila) variety for field experiment were used with Tutan36%SC (insecticide with active ingredient of Chlorphenapyr 36%SC) and untreated plots as positive and negative controls, respectively. The results showed significant leaf and fruit damage reduction in all the treatments. B. bassiana-AAUB03, M. anisopliae-AAUM78, and B. thuringiensis-AAUF6 showed the highest (93.4%, 89.7% and 90.1%) leaf and (93.5%, 94.4% and 95%) fruit protection under greenhouse condition. The combined treatments improved leaf protection efficacy up to 95.3% under field condition. When the entomopathogens were combined with half or quarter reduced concentrations of Tutan36% SC, it showed 94.4% of pest protection. In all the treatments, 72-96% of marketable fruit was obtained as par insecticide treatment scored 85-93%. All the entomopathogens did not cause any adverse effect on the growth of tomato rather improved shoot length, shoot branching, leaf and fruit numbers. Therefore, application of entomopathogens in single, consortium or in combination reduced the recommended concentration of Tutan36%SC to control T. absoluta.

Molecular phylogeny and pathogenicity of indigenous Beauveria bassiana against the tomato leafminer, Tuta absoluta Meyrick 1917 (Lepidoptera: Gelechiidae), in Ethiopia.

BACKGROUND: Tuta absoluta Meyrick 1917 (Lepidoptera: Gelechiidae) is an invasive, pesticide resistant, and a major treat of tomato production in the world. It needs effective management options that naturally infect the insect without causing any identified side effects. Entomopathogenic fungi (EPF) are the most important options. However, geographic origin and climatic condition apparently creates genetic variation among EPF strains that influence on their pathogenicity. Thus, screening of effective EPF strains from the local source is vital to develop environmental friendly pest control tactic for T. absoluta. RESULTS: In this study, 27 indigenous Beauveria were isolated from the various types of soil and 12 of the isolates were screened based on their biological efficiency index (BEI). These isolates scored 65.7-95.7% and 68.3-95% of mortality against second and third instar larvae of T. absoluta at concentration of 1 × 107spores·ml-1 in 7 days post inoculation, respectively. Out of these, five (18.5%) isolates scored above 90% mortality on both instar larvae with LT50 value of 3.33 to 5.33 days at the lowest (104 spores·ml-1) and 1.93 to 3.17 days at highest (108 spores·ml-1) spore concentrations and has LC50 value of 1.5 × 103 to 1.1× 105 spores·ml-1. Moreover, isolates exhibited the promising mortality better (1.5 × 106 to 3.5 × 107 spores·ml-1), sporulated over the larval cadavers, well grown at optimal temperature, and produced chitinolytic enzymes. Molecular analysis showed that isolates have nearly monophyletic characters and grouped under species of Beauveria bassiana. CONCLUSION: Different types of soil in Ethiopia are an important source of B. bassiana, and these isolates showed promising pathogenicity against T. absoluta, which is crucial for ecofriendly biopesticide development. Although isolates were nearly monophyletic in phylogenetic study, five of them were highly effective in the laboratory bioassays against T. absoluta; however, further field evaluation is required for mass production.

Isolation, molecular characterization and pathogenicity of native Bacillus thuringiensis, from Ethiopia, against the tomato leafminer, Tuta absoluta: Detection of a new high lethal phylogenetic group.

Tuta absoluta (tomato leafminer) is one of the devastating agricultural pest that attack mainly tomatoes. The continuous use of chemical pesticides is not affordable and poses a collateral damage to human and environmental health. This requires integrated pest management to reduce chemical pesticides. B. thuringiensis is a cosmopolitan, antagonistic soil bacterium used to control agricultural pests. In this study, effective Bt strains were screened from different sample sources based on their lepidopteran specific cry genes and larvicidal efficacy against tomato leafminer, T. absoluta under laboratory conditions. Of the 182 bacterial isolates, 55 (30 %) of isolates harbored parasporal protein crystals. Out of these, 34 (62 %) isolates possess one or more lepidopteran specific cry genes: 20 % of isolates positive for cry2, 18.2 % for cry9, 3.6 % for cry1, 16.4 % for cry2 + cry9, 1.8 % for cry1 + cry9, and 1.8 % for cry1 + cry2 + cry9. However, 21 (38.2 %) isolates did not show any lepidopteran specific cry genes. Isolates positive for cry genes showed 36.7-75 % and 46.7-98.3 % mortality against second and third instar larvae of the T. absoluta at the concentration of 108 colony forming units (CFUs) ml-1. Cry1 and cry1 plus other cry gene positive isolates were relatively more pathogenic against T. absoluta. However, third instar larvae of the T. absoluta was more susceptible than second instar larvae. Two of the isolates, AAUF6 and AAUMF9 were effective and scored LT50 values of 2.3 and 2.7 days and LC50 values of 3.4 × 103 and 4.15 × 103 CFUs ml-1 against the third instar larvae, respectively. The phylogenetic studies showed some congruence of groups with cry gene profiles and lethality level of isolates and very interestingly, we have detected a putative new phylogenetic group of Bt from Ethiopia.

Genetic and metabolic diversities of rhizobacteria isolated from degraded soil of Ethiopia.

Genetic and metabolic diversities of rhizobacteria are the fundamental sources for their adaptation to cope with abiotic and biotic stresses in order to enhance growth and health of plants in the soil. Thus, this study was initiated to assess the genetic and metabolic diversities of rhizobacteria isolated from plants grown in degraded soil through BOX-PCR and partial sequencing of 16S rRNA genes. A total of eighty isolates were recovered and subjected to phenotypic profiling of carbohydrate and amino acid utilization, BOX PCR and 16S rRNA profiling. The phenotypic profiling showed remarkable metabolic versatility with Ochrobactrum spp, Pseudomonas spp and Klebsiella spp, and BOX-PCR showed greater discriminatory power for fingerprinting of rhizobacterial isolates with high degree of polymorphism. Bacillus spp showed the highest Simpson's diversity Index. The 16S rRNA genes sequence assigned the rhizobacteria to phyla Proteobacteria with Gammaproteobacteria and Alphaproteobacteria classes and Firmicutes with Bacilli class. The data also showed that the most dominant species were Pseudomonas and Ochrobactrum. Genetic and metabolic diversities of the rhizobacterial isolates reveal the potential of these microbes for plant growth improvement under water deficient soil after testing other inoculant traits.

Plant Growth-Promoting Rhizobacteria Isolated from Degraded Habitat Enhance Drought Tolerance of Acacia (Acacia abyssinica Hochst. ex Benth.) Seedlings.

Drought stress (DS) is the most impacting global phenomenon affecting the ecological balance of a particular habitat. The search for potential plant growth-promoting rhizobacteria (PGPR) capable of enhancing plant tolerance to drought stress is needed. Thus, this study was initiated to evaluate the effect of inoculating Acacia abyssinica seedlings with PGPR isolated from rhizosphere soil of Ethiopia to enhance DS tolerance. The strains were selected based on in vitro assays associated with tolerance to drought and other beneficial traits such as salinity, acidity, temperature, heavy metal tolerances, biofilm formation, and exopolysaccharide (EPS) production. The strains with the best DS tolerance ability were selected for the greenhouse trials with acacia plants. The results indicate that out of 73 strains, 10 (14%) were completely tolerant to 40% polyethylene glycol. Moreover, 37% of the strains were strong biofilm producers, while 66 (90.41%) were EPS producers with a better production in the medium containing sucrose at 28 ± 2°C and pH 7 ± 0.2. Strains PS-16 and RS-79 showed tolerance to 11% NaCl. All the strains were able to grow in wider ranges of pH (4-10) and temperature (15-45°C) and had high tolerance to heavy metals. The inoculated bacterial strains significantly (p ≤ 0.05) increased root and shoot length and dry biomass of acacia plants. One of the strains identified as P. fluorescens strain FB-49 was outstanding in enhancing DS tolerance compared to the single inoculants and comparable to consortia. Stress-tolerant PGPR could be used to enhance acacia DS tolerance after testing other phytobeneficial traits.

Corrigendum to "In Vitro Evaluation of Probiotic Properties of Lactic Acid Bacteria Isolated from Some Traditionally Fermented Ethiopian Food Products".

[This corrects the article DOI: 10.1155/2019/7179514.].

Molecular identification and performance evaluation of wild yeasts from different Ethiopian fermented products.

Different types of yeasts and lactic acid bacteria dominate in spontaneously fermented products (food, beverages, and condiments) that are commonly consumed in Ethiopia. The aim of this study was to identify efficient fermentative yeasts from fermented foods, fermented beverages, honey and molasses using genotypic methods. Out of the 70 samples tested, 180 distinct wild yeast isolates were recovered. A total of 23 isolates were selected for genomic analysis based on their basis of biomass yield, fermentation capacity, and leavening performance. The nucleotide sequence analysis of the internal transcribed spacer ITS-5.8S rDNA region revealed that the indigenous yeast isolates had close relatedness to Saccharomyces cerevisiae, Candida humilis, Kazachstania bulderi, Pichia fermentans and Pichia kudriavzevii with greater than 97% nucleotide similarity. The study shows a high diversity of indigenous wild yeasts in fermented products and that potent strains had higher biomass yield, good gas production and remarkable leavening capacity that indicates their inherent potential for use in the baking industry.

Protective Effect of Potential Probiotic Strains from Fermented Ethiopian Food against Salmonella Typhimurium DT104 in Mice.

Salmonella is one of the most harmful pathogens responsible for foodborne outbreaks, illnesses and deaths. The aim of this study was to evaluate the effect of potentially probiotic strains against Salmonella Typhimurium DT104 in mice. The compatibility test among the selected potential probiotic strains (Lactobacillus plantarum K132, Lactobacillus paracasei K114 and Lactococcus lactis E124) using the cross-streaking method showed the absence of antagonism. The anti-Salmonella activities of coculture of the isolated potential probiotics in the form of mixed or single culture showed a remarkable anti-Salmonella activity with 96.50 to 100% growth inhibition. The combination of strains, which showed the highest growth inhibition rates against Salmonella Typhimurium DT104, was used to test their effect on the colonization of mice by Salmonella Typhimurium DT104. White albino male mice were pretreated with the mixed potential probiotics for 7 days and infected with Salmonella Typhimurium DT104 for 1 day. A total of 3 treatments were applied, during which the negative control group was treated with phosphate-buffered saline (PBS); a positive control group (typ) was challenged with Salmonella Typhimurium DT104 alone. The treated group (pro-typ) was pretreated with mixed potential probiotic culture and then infected with Salmonella Typhimurium DT104. The survival rate of mice and counts of Salmonella in feces were recorded. The survival rate of mice on day 21 after the oral challenge with Salmonella Typhimurium DT104 was significantly (p < 0.05) higher in the experimental pro-typ group (100% survival) compared with the positive control group (20% survival). The counts (colony-forming unit per ml) of Salmonella in feces were significantly lower (p < 0.05) for the pro-typ group compared to the typ group. The combination of potential probiotic strains was able to protect mice against Salmonella Typhimurium DT104 infection that demonstrates their potential to be used as probiotic cultures for the production of functional fermented products.

In Vitro Evaluation of Probiotic Properties of Lactic Acid Bacteria Isolated from Some Traditionally Fermented Ethiopian Food Products.

Probiotics are live microorganisms which when consumed in large number together with a food promote the health of the consumer. The aim of this study was to evaluate in vitro probiotic properties of lactic acid bacteria (LAB) isolated from traditional Ethiopian fermented Teff injera dough, Ergo, and Kocho products. A total of 90 LAB were isolated, of which 4 (4.44%) isolates showed 45.35-97.11% and 38.40-90.49% survival rates at pH values (2, 2.5, and 3) for 3 and 6 h, in that order. The four acid-tolerant isolates were found tolerant to 0.3% bile salt for 24 h with 91.37 to 97.22% rate of survival. The acid-and-bile salt-tolerant LAB isolates were found inhibiting some food-borne test pathogenic bacteria to varying degrees. All acid-and-bile-tolerant isolates displayed varying sensitivity to different antibiotics. The in vitro adherence to stainless steel plates of the 4 screened probiotic LAB isolates were ranged from 32.75 to 36.30% adhesion rate. The four efficient probiotic LAB isolates that belonged to Lactobacillus species were identified to the strain level using 16S rDNA gene sequence comparisons and, namely, were Lactobacillus plantarum strain CIP 103151, Lactobacillus paracasei subsp. tolerans strain NBRC 15906, Lactobacillus paracasei strain NBRC 15889, and Lactobacillus plantarum strain JCM 1149. The four Lactobacillus strains were found to be potentially useful to produce probiotic products.

Phytochemical Composition and Antioxidant Property of Mandillo, Crassocephalum macropappum (Sch.Bip. ex. A.Rich.) S.Moore.

The object of this study was to analyze the major bioactive components and to evaluate biological activity of Mandillo [Crassocephalum macropappum (Sch.Bip. ex. A.Rich.) S. Moore], an Ethiopian endemic herbaceous plant. The stem, leaf, and aerial parts of this plant were separately extracted using different solvents before which various biological assays were performed. The ethanolic extract of aerial part showed the highest total phenolic and flavonoid contents (101.48 mg gallic acid equivalents/g and 293.25 mg quercetin equivalent/g, respectively). Interestingly, a phytochemical screening assay revealed the presence of saponins, tannins, anthraquinones, steroids, terpenoids, and flavonoids in the aerial part. The aerial part was also shown to have a strong 2,2-diphenyl-1-picryl hydrazyl scavenging potential (IC50≤100 µg/mL) and a promising protective activity against oxidative DNA damage. Thus, the results of the present study reveal Mandillo contains highly bioactive components, and these properties may be as an antioxidant and to prevent oxidative DNA damage.

Molecular Characterization of Fermenting Yeast Species from Fermented Teff Dough during Preparation of Injera Using ITS DNA Sequence.

Identification of the yeast responsible for Injera fermentation is important in order to be more consistent and for scale-up of Injera production. In this study, yeast were isolated and identified from fermenting teff dough sample collected from household, hotels, and microenterprises, Addis Ababa. Initially, the yeast obtained from fermenting teff dough of different sources were selected on the basis of their CO2 production potentials. Its DNA sequencing of isolated yeast identified Pichia fermentans, Pichia occidentalis, Candida humilis, Saccharomyces cerevisiae, and Kazachstania bulderi. The association of identified yeast to their sources indicated the presence of Pichia fermentans in fermenting dough samples collected from all sources whereas Kazachstania bulderi, Saccharomyces cerevisiae, and Candida humilis were shown to be present in samples collected from households, hotels, and microenterprises, respectively. The phenotypes and CO2 production potentials of this yeast were also documented. This study has confirmed the presence of different yeast species in the fermentation of teff dough and hinted the complex nature of Injera dough fermentation.

Isolation and Molecular Identification of Lactic Acid Bacteria Using 16s rRNA Genes from Fermented Teff (Eragrostis tef (Zucc.)) Dough.

Injera is soft fermented baked product, which is commonly prepared from teff (Eragrostis tef (Zucc.)) flour and believed to be consumed on daily basis by two-thirds of Ethiopians. As it is a product of naturally fermented dough, the course of fermentation is done by consortia of microorganisms. The study was aimed at isolating and identifying some dominant bacteria from fermenting teff (Eragrostis tef) dough. A total of 97 dough samples were collected from households, microenterprises, and hotels with different fermentation stage from Addis Ababa. The bacterial isolates obtained from the fermenting teff dough samples were selected on the basis of their acid production potentials. A total of 24 purified bacterial isolates were found to be Gram-positive (they are coccus and rod under microscope) and were good acid producers. Genomic DNA of bacterial isolates were extracted using Invisorb® Spin DNA Extraction kit. 16S rRNA of bacterial isolates were amplified using the bacteria universal primers (rD1 and fD1). The amplified product was sequenced at Genewiz, USA. Sequence analysis and comparison with the resources at the database were conducted to identify the isolated microbes into species and strain levels. The bacterial isolates were identified as Lactobacillus paracasei, Lactobacillus brevis, Enterococcus durans, Enterococcus hirae, Enterococcus avium, and Enterococcus faecium. All identified lactic acid bacteria were able to produce acid at 12 h time of incubation. This study has confirmed the presence of different bacterial species in the fermenting teff dough and also supports the involvement of various groups of bacterial species in the course of the fermentation.

Potential Applications of Some Indigenous Bacteria Isolated from Polluted Areas in the Treatment of Brewery Effluents.

Biological wastewater treatment is economically feasible and ecofriendly. This study was aimed at isolating bacteria from brewery wastes and evaluating their bioremediation potential as individual isolate and/or their consortium in reducing the pollutants of brewery effluents. A total of 40 bacterial isolates were recovered and of these the three best isolates were selected. The selected bacteria were identified to genus level by using morphological and biochemical characteristics. Accordingly, the isolates were identified as Aeromonas sp., Pseudomonas sp., and Bacillus sp. After 12 days of incubation, the removal efficiency of these three isolates and their combinations for biological oxygen demand and chemical oxygen demand varied from 73.55% to 94.85% and 76.78% to 93.25%, respectively. Total nitrogen and phosphorus removal was within the range of 54.43% to 77.21% and 41.80% to 78.18%, respectively. Total suspended solid, total solid, and total dissolved solids removal ranged from 66.74% to 90.3%, 54.69% to 88.5%, and 53.02% to 88.2%, respectively. The pH and electrical conductivity values ranged from 6.81 to 8.65 and 3.31 mS/cm to 3.67 mS/cm, respectively. The treated effluent increased Beta vulgaris seeds germination from 80% to 100%, with mean germination time of 3.1 to 5.2 days and seedlings length of 2.3 cm to 6.3 cm. Therefore, the development of this finding into a large scale offers an attractive technology for brewery waste treatment.

Phosphate Solubilization Potential of Rhizosphere Fungi Isolated from Plants in Jimma Zone, Southwest Ethiopia.

Phosphorus (P) is one of the major bioelements limiting agricultural production. Phosphate solubilizing fungi play a noteworthy role in increasing the bioavailability of soil phosphates for plants. The present study was aimed at isolating and characterizing phosphate solubilizing fungi from different rhizospheres using both solid and liquid Pikovskaya (PVK) medium. A total of 359 fungal isolates were obtained from 150 rhizosphere soil samples of haricot bean, faba bean, cabbage, tomato, and sugarcane. Among the isolates, 167 (46.52%) solubilized inorganic phosphate. The isolated phosphate solubilizing fungi belonged to genera of Aspergillus (55.69%), Penicillium spp. (23.35%), and Fusarium (9.58%). Solubilization index (SI) ranged from 1.10 to 3.05. Isolates designated as JUHbF95 (Aspergillus sp.) and JUFbF59 (Penicillium sp.) solubilized maximum amount of P 728.77 µg·mL(-1) and 514.44 µg mL(-1), respectively, from TCP (tricalcium phosphate) after 15 days of incubation. The highest (363 µg mL(-1)) soluble-P was released from RP with the inoculation of JUHbF95 in the PVK broth after 10 days of incubation. The present study indicated the presence of diverse plant associated P-solubilizing fungi that may serve as potential biofertilizers.