Indigenous Strains Research Articles

Indigenous microalgae strains characterization for a sustainable biodiesel production.

Microalgae have been widely recognized as a promising feedstock for sustainable biofuels production to tackle global warming and pollution issues related to fossil fuels uses. This study identified and analyzed indigenous microalgae strains for biodiesel production, specifically Chlorella vulgaris and Coelastrella thermophila var. globulina, from two distinct locations in Algeria. Molecular identification confirmed their identity, and the microalgae exhibited notable growth characteristics. Local Chlorella vulgaris and Coelastrella thermophila var. globulina showed good growth and high biomass yield, compared to Chlorella vulgaris CCAP211/11B reaching a weight of 1.48 gL-1 , 1.95 gL-1 , and 2.10 gL-1 , respectively. Lipids content of local Chlorella vulgaris, Coelastrella thermophila var. globulina, and Chlorella vulgaris CCAP211/11B, were found to be 31.39±3.3%, 17±2.26%, and 19±0.64%, respectively. Chlorella vulgaris stood out as a candidate for biodiesel production due to its equilibrium between SFA and PUFA (43.24% and 45.27%). FAs are predominated by SFA and MUFA for Coelastrella thermophila var. globulina with value of 81.49% (SFA+MUFA). Predicted biodiesel qualities comply with ASTM6751 and EN14214 standards. Studied microalgae have therefore a promising potential for biodiesel production. However, optimising cultivation conditions is necessary to enhance biomass and lipids yield at a large scale.

Rhizoglomus variabile and Nanoglomus plukenetiae, Native to Peru, Promote Coffee Growth in Western Amazonia.

Coffee (Coffea arabica) is among the world's most economically important crops. Coffee was shown to be highly dependent on arbuscular mycorrhizal fungi (AMF) in traditionally managed coffee plantations in the tropics. The objective of this study was to assess AMF species richness in coffee plantations of four provinces in Perú, to isolate AMF isolates native to these provinces, and to test the effects of selected indigenous AMF strains on coffee growth. AMF species were identified by morphological tools on the genus level, and if possible further to the species level. Two native species, Rhizoglomus variabile and Nanoglomus plukenetiae, recently described from the Peruvian mountain ranges, were successfully cultured in the greenhouse on host plants. In two independent experiments, both species were assessed for their ability to colonize coffee seedlings and improve coffee growth over 135 days. A total of 35 AMF morphospecies were identified from 12 plantations. The two inoculated species effectively colonized coffee roots, which resulted in 3.0-8.6 times higher shoot, root and total biomass, when compared to the non-mycorrhizal controls. R. variabile was superior to N. plukenetiae in all measured parameters, increasing shoot, root, and total biomass dry weight by 4.7, 8.6 and 5.5 times, respectively. The dual inoculation of both species, however, did not further improve plant growth, when compared to single-species inoculations. The colonization of coffee by either R. variabile or N. plukenetiae strongly enhances coffee plant growth. R. variabile, in particular, offers enormous potential for improving coffee establishment and productivity. Assessment of further AMF species, including species from other AMF families should be considered for optimization of coffee growth promotion, both alone and in combination with R. variabile.

Treatment of 2-naphthalene sulfonate by free and immobilized cells of indigenous isolate Comamonas sp. C2 and toxicity evaluation of biotransformed sample

An indigenous bacterial strain Comamonas sp. C2, capable of utilizing 2-naphthalene sulfonate (2-NS) as a sole source of carbon, was isolated after enrichment of microbial diversity present in sample collected from sewage treatment plant (STP) receiving untreated or partially treated effluent from textile industries. The isolate was able to degrade 100 mg/L of 2-NS, when grown in sulfur free minimal salt medium (SFMSM), after an incubation of 8 h. The release of sulfite/sulfate ions during biotransformation, assay of protocatechuate 4, 5-dioxygenase activity and formation of metabolic intermediates like salicylaldehyde, protocatechuate and 2-hydroxy-4-carboxy-muconatesemialdehyde in the biologically treated sample indicated to the meta-cleavage of aromatic ring of 2-NS. An immobilized-cell plug flow bioreactor (PFR) was developed and evaluated for its efficiency to treat simulated feed supplemented with 100 mg/L of 2-NS. The cells of C2 were immobilized on pieces of polyurethane foam (PUF) and refractory brick pieces (RBP). The PFR, when operated at an HRT of 36 h, achieved complete degradation of 100 mg/L of 2-NS corresponding to 89% lowering of COD. The reduction in overall toxicity of 2-NS after biological treatment was evaluated using plant (Triticum aestivum and Vigna radiata) and animal (freshwater fish Channa punctatus) models, exposed to both untreated and PFR treated samples. To the best of our knowledge, there are no similar reports on exploitation of the metabolic potential of Comamonas sp. in 2-NS degradation and validation of the biological transformation by toxicity analysis.

Indigenous fungal strains isolation and molecular identification from coffee pulp for the production of pectic oligosaccharides.

The online version contains supplementary material available at 10.1007/s13205-023-03811-9.

Effect of Fortified Inoculation with Indigenous Lactobacillus brevis on Solid-State Fermentation of Light-Flavor Baijiu.

Baijiu, one of the world's oldest distilled liquors, is widely consumed globally and has gained increasing popularity in East Asia. However, a comprehensive understanding of the underlying principles behind this traditional liquor product remains elusive. Currently, Baijiu is facing the industrial challenge of modernization and standardization, particularly in terms of food quality, safety, and sustainability. The current study selected a Lactobacillus brevis strain based on experiments conducted to assess its environmental tolerance, enzyme activity, and fermentation performance, and highlight its exceptional fermentation characteristics. The subsequent analysis focused on examining the effects of fortifying the fermentation process of L.brevis on key microbiotas, physicochemical parameters, and volatile profiles. The qPCR results revealed that the inoculated L. brevis strategically influenced the the composition of the dominant microbial communities by promoting mutual exclusion, ultimately leading to improved controllability of the fermentation process. Moreover, the metabolism of the inoculated L. brevis provided more compounds for the formation of flavor profiles during fermentation (the content of ethyl acetate was increased to 57.76 mg/kg), leading to a reduction in fermentation time (from 28 d to 21 d). These findings indicate promising potential for the application of the indigenous strain in Baijiu production.

Transcriptomic Comparison of Liver Tissue across Different Largemouth Bass (Micropterus salmoides) Strains

Over the past few years, China has become a hotspot for the domestication of the commercially valuable largemouth bass (Micropterus salmoides). Although the food preference of this fish has been studied, little is known about the genes regulating its growth. Population breeding was performed using two indigenous strains (QT1 and QT2), with the results showing that the organ/body ratio, abdominal fat rate and the body weight gain of QT1 and QT2 were higher than for the offspring YL1 and Y3 which are extensively cultured in China. Subsequent RNA sequencing (RNA-Seq) allowed for the identification of potential genes and pathways involved in growth performance. Overall, the transcriptome analysis generated 89,056 transcripts and 42,529 Unigenes. A PCA revealed significant differences between QT1 and the other three strains, while the other three strains did not show much difference. A KEGG enrichment analysis of differentially expressed genes showed that steroid biosynthesis was the most enriched pathway among the four strains. These pathways could be related to the growth of largemouth bass. In addition, a co-expression network analysis suggested a strong interaction between liver steroid biosynthesis and the genes for photosynthesis, secondary metabolism and stress response. Taken together, the above results can provide new insights into the liver metabolism of different strains of largemouth bass during culture and provide references for the subsequent domestication and breeding programs of largemouth bass.

Bioremediation of Cr(VI) using indigenous bacterial strains isolated from a common industrial effluent treatment plant in Vishakhapatnam

Abstract The present study focuses on removing hexavalent chromium (Cr(VI)) using indigenous metal-resistant bacterial strains isolated from a common industrial effluent treatment plant, a contaminated site in Vishakhapatnam. Three high metal-resistant isolates were screened by growing them in nutrient agar media containing different Cr(VI) concentrations for 24 h at 35 ± 2 °C. The three strains’ minimum inhibitory concentrations of Cr(VI) were examined at neutral pH and 35 ± 2 °C temperature. Morphological, biochemical, and molecular characterizations were carried out, and the strains were identified as Bacillus subtilis NITSP1, Rhizobium pusense NITSP2, and Pseudomonas aeruginosa NITSP3. Elemental composition and functional group analysis of the native and metal-loaded cells were done using energy-dispersive spectroscopy and Fourier-transform infrared spectroscopy, respectively. The operating conditions were optimized using a one-factor-at-a-time analysis. When compared with three bacterial isolates, maximum Cr(VI) removal (80.194 ± 4.0%) was observed with Bacillus subtilis NITSP1 with an initial Cr(VI) concentration of 60 mg/L, pH 7.0, an inoculum size of 2% (v/v), and an incubation period of 24 h. The logistic model was used to predict the variation of biomass growth with time. The present study can be extended to remove heavy metals from industrial wastewater in an environmental-friendly manner.

Extraction of High Economic Potential of Lipids from Heterotrophic Cultivation of Indigenous Aurantiochytrium Microalgae Strain

Extraction of High Economic Potential of Lipids from Heterotrophic Cultivation of Indigenous Aurantiochytrium Microalgae Strain

Abiotic factors improving fatty acid profiling of freshwater indigenous microalgae isolated from Kumaun region of Uttarakhand, India.

Microalgae have grabbed huge attention as a potential feedstock for biofuel production in response to the rise in energy consumption and the energy crisis. In the present study, indigenous microalgal strains were isolated from four freshwater lakes in the Kumaun region, Uttarakhand, India. Based on growth and lipid profiles, the four best-performing isolates were selected for further experiments. Initial identification of isolates was done by morphological observations, which were further validated by molecular identification using ITS sequencing. The screened cultures were subjected to abiotic stress conditions (varying concentrations of nitrogen and different temperatures) to monitor the biomass, lipid accumulation, and biochemical compositions (chlorophyll and carotenoids). The quantification of fatty acids was checked via gas chromatographic analysis. The strains were identified as KU_MA3 Chlamydopodium starrii, KU_MA4 Tetradesmus nygaardii, KU_MA5 Desmodesmus intermedius, and KU_MA6 Tetradesmus nygaardii. KU_MA3 Chlamydopodium starrii showed the best results in terms of growth and lipid production at 21 °C and 0.37 g/L NaNO2 concentration. The percentage of fatty acid methyl esters (FAMEs) attained >80% and met the standard for biodiesel properties. The strain has the potential to attain higher biomass and accumulate higher lipid content, and after some more studies, it can be used for upscaling processes and large-scale biodiesel production.

Bioremediation of uranium (Ⅵ) using a native strain Halomonas campaniensis ZFSY-04 isolated from uranium mining and milling effluent: Potential and mechanism

A significant surge in the exploitation of uranium resources has resulted in considerable amounts of radioactive effluents. Thus, efficient and eco-friendly uranium removal strategies need to be explored to ensure ecological safety and resource recovery. In this study, we investigated the resistance of Halomonas campaniensis strain ZFSY-04, isolated from an evaporation pool at a uranium mine site, and its potential mechanism of uranium (Ⅵ) removal. The results showed that the strain exhibited unique uranium tolerance and its growth was not significantly inhibited under a uranium concentration of 700 mg/L. It had a maximum loading capacity of 865.40 mg/g (dry weight), achieved following incubation under uranium concentration of 100 mg/L, pH 6.0, and temperature 30 °C, for 2 h, indicating that the removal of uranium by the strain was efficient and rapid. Combined with kinetic, isothermal, thermodynamic, and microspectral analyses, the mechanism of uranium loading by strain ZFSY-04 was metabolism-dependent and diverse, including, physical and chemical adsorption on the cell surface, extracellular biomineralisation, intracellular bioaccumulation, and biomineralisation. Our results highlight the unique properties of indigenous strains, including high resistance, high efficiency, rapid uranium removal, and various uranium removal strategies, which make it suitable as a new tool for in situ bioremediation and uranium-contaminated environmental resource recovery.

Utilization of pretreated oil palm empty fruit bunches and their hydrolysate for ethanol production by Indonesian ethanologenic yeast

Abstract. Anita SH, Oktaviani M, Hermiati E. 2023. Utilization of pretreated oil palm empty fruit bunches and their hydrolysate for ethanol production by Indonesian ethanologenic yeast. Biodiversitas 24: 5243-5252. Oil Palm Empty Fruit Bunches (OPEFB) represent a polysaccharide-rich raw material with promising potential for ethanol production. This study aimed to investigate the ethanologenic yeasts, specifically Saccharomyces cerevisiae InaCC Y93 and Kluyveromyces marxianus InaCC Y119, affect bioethanol production in three different systems: Separate Hydrolysis and Fermentation (SHF), Simultaneous Saccharification and Fermentation (SSF), and Prehydrolysis-Simultaneous Saccharification and Fermentation (PSSF). This work is distinguished by the use of indigenous Indonesian yeast strains, including a thermotolerant strain. In the pretreatment process, 1.13% oxalic acid was added to OPEFB and subjected to microwave treatment at 190°C for 3.01 min. Subsequently, cellulase enzymes (40 FPU/g) and a 10% (w/v) yeast inoculum were introduced into 5.27 g dry weight of pretreated OPEFB pulp. The OPEFB acid hydrolysate was also subjected to fermentation. Ethanol content was monitored at 24 h intervals for 72 h. The PSSF system employs K. marxianus InaCC Y119 at 48 h exhibited the highest ethanol concentration, yielding 0.290 g/g, equivalent to approximately 51.20% of the theoretical yield. Additionally, K. marxianus InaCC Y119 demonstrated its capability to ferment the OPEFB acid hydrolysate into ethanol. These findings underscore the considerable potential of K. marxianus for applications in fermenting both hexose and pentose sugars to produce ethanol within higher-temperature systems.

Single versus dual inoculation with indigenous Saccharomyces cerevisiae strains in winemaking.

Indigenous Saccharomyces cerevisiae strains and their combinations may be used to diversify wines and add complexity to sensory profiles. Here, two S. cerevisiae strains that represent regional genetic and phenotypic specificities for two major winegrowing areas of Greece were used in single- and mixed-culture fermentations. The kinetics and metabolic activities of the strains were analysed to evaluate the influence of each strain individually or in combination on wine quality. The two strains differentially affected the kinetics and the outcome of fermentation. They showed significant differences in the production of important metabolites that strongly affect the organoleptic profile of wines, such as volatile acidity, acetaldehyde, certain esters, and terpenes. Furthermore, the chemical and sensory profiles of wines produced by single cultures were different from those fermented by mixed culture inoculum. The concentration of certain metabolites was enhanced (e.g. isoamyl acetate, 1-heptanol), while others were suppressed (e.g. hexyl acetate, octyl acetate). Results highlight the potential worth of indigenous S. cerevisiae strains to differentiate local wines. The mixed culture S. cerevisiae inoculum was shown to generate novel wine characteristics, as compared to single cultures, thus offering alternatives to further diversify wines and increase their complexity.

Solarized IPM Module for Biocontrol of Root-knot Nematode on Tomato at Nursery Level in District G.B Nagar, Uttar Pradesh

Background: The role of soil solarization in suppression of soil borne pathogens and weeds has been established by several researchers around the globe It involves capturing solar radiations when the soil receives the maximum sunlight in May-June using a polythene mulch. Its effectiveness depends on ambient temperature, duration of the treatments and soil moisture. This not only acts as a soil disinfectant but also as soil decontamination. It includes various changes in the soil like physical, chemical and biological properties. Methods: The field to lab and vice-versal based investigations were carried during 2021-2022 at Amity Centre for Biocontrol and Plant Disease Management, Amity University, Uttar Pradesh, Noida and identified tomato nurseries of district G B Nagar where heavy infestation (10-12 J2/cc soil) of root knot nematode, Meloidogyne incognita (Kofoid and White) Chitwood was recorded. The treatments comprised of sustainable components viz. deoiled seed cake of neem, a Arbuscular Mycorrhizal fungus Glomus intraradices and indigenous fungal strain of Trichoderma harzianum, (Th7) alone and together applied for evolving IPM module at solarized and unsolarized sets. Under microplot trials, the entire solarized treatments were carried out measuring 3 × 1 sq. meter each in which one set of all the treatments including control covered with clear transparent polythene sheet (400 ì gauge) for solarization. The treatments were replicated thrice in randomized block design. Result: The observations of solarized and unsolarized treatments clearly revealed that the soil solarization in treatments where the sun radiant energy was trapped by 400 µ transparent polysheets significantly reduced the root knot nematode Meloidogyne incognita population both in root and soil in comparison to unsolarized treatments where no solar energy trapping was done. The combined application of locally isolated Trichoderma harzianum (Th7) and VA mycorrhiza, Glomus intraredices enhanced germination and plant growth in nurseries. In the present investigation, the solarized IPM module- 4 comprising of other sustainable components viz. neem oil-seed cake, T. harzianum (Th-7) and Arbuscular Mycorrhizal (AM) fungus G. intraredices is proved to be an ideal one in root-knot nematode pest management in tomato nurseries.

Red pigment from isolated Serratia marcescens SEM: Structure, antimicrobial and antioxidant activity

Pigments from microbial sources are likely to be suitable alternatives to synthetic pigments. Not only do natural pigments have the potential to increase product marketability, but they also exhibit valuable biological activities as antioxidants and antimicrobial agents. Recently, microbial prodigiosin (PG) has received a lot of attention due to its many beneficial applications. PG is a natural red dye. It is an alkaloid secondary metabolite with a unique tertiary structure produced by Serratia marcescens. The purpose of our study was to isolate indigenous strains of S. marcescens and identify it, extraction the red pigment from culturable bacteria to confirm its structure, evaluate its antimicrobial activity against a series of pathogenic microbes (Staphylococcus aureus NRRL B-313 and Bacillus subtilus NRC, Escherichia coli NRC B-3703, Pseudomonas aeruginosa NRC B-32, Candida albicans ATCC1023 and Aspergillus niger NRC) by well diffusion assay and antioxidant activities by DPPH assay. The isolate was identified by morphological characteristics and 16S rRNA sequencing as S. marcescens SEM, with accession number OM757735.1. PG from S. marcescens was first confirmed its purity by UV absorption spectrum, FTIR and GC-MS spectrophotometer. PG possess effective antimicrobial activity against tested pathogens, with MIC 1.0 ± 0.15, 5.0 ± 0.25, 16.5 ± 0.87, 16.5 ± 0.92 and 3.3 ± 0.17 μg/mL against B. cereus, St. aureus, E. coli, P. aurgenosa, and C. albicans, respectively. Also, PG possess highly antioxidant activity 97.2% at the concentration of 400 μg/ml after 120 min in dark, this activity increased gradually with increasing concentrations and time of incubation in dark,with IC50 (250 μg/ml at 30 min; 225 μg/ml at 60 min; 200 μg/ml at 90 min; 125 μg/ml at 120 min).

Towards inoculant development for Bambara groundnut (Vigna subterranean (L.) Verdc) pulse crop production in Namibia.

The globally expanding population, together with climate change, poses a risk to the availability of food for humankind. Bambara groundnut (BGN) (Vigna subterranea (L.) Verdc) is a neglected, relatively drought-tolerant native legume of Sub-Saharan Africa that has the potential to become a successful food crop because of its nutritional quality and climate-smart features. Nitrogen fixation from root nodule symbiosis with climate-adapted rhizobial symbionts can contribute nitrogen and organic material in nutrient-poor soil and improve yields. However, high soil temperature and drought often reduce the abundance of native rhizobia in such soil. Therefore, the formulation of climate-smart biofertilizers has the potential to improve the farming of BGN at a low cost in a sustainable manner. The effect of seven Bradyrhizobium spp. strains native to Namibia, including B. vignae and B. subterraneum, were tested on three Namibian BGN varieties (red, brown, cream) in greenhouse pot experiments in Namibia, using soil from the target region of Kavango. Each variety was treated with a mixed inoculant consisting of seven preselected strains ("MK") as well as with one promising single inoculant strain. The results revealed that in all three varieties, the two inoculants (mixed or single) outperformed the non-inoculated cultivars in terms of shoot dry weight by up to 70%; the mixed inoculant treatment performed significantly better (p < 0.05) in all cases compared to the single inoculant used. To test whether the inoculant strains were established in root nodules, they were identified by sequence analysis. In many cases, the indigenous strains of Kavango soil outcompeted the inoculant strains of the mix for nodule occupancy, depending on the BGN variety. As a further preselection, each of the individual strains of the mix was used to inoculate the three varieties under sterile conditions in a phytotron. The agronomic trait and root nodulation response of the host plant inoculations strongly differed with the BGN variety. Even competitiveness in nodule occupancy without involving any indigenous strains from soil differed and depended strictly on the variety. Severe differences in symbiont-plant interactions appear to occur in BGN depending on the plant variety, demanding for coupling of breeding efforts with selecting efficient inoculant strains.

Genetic Diversity of Aspergillus flavus on Maize in Guatemala.

Aflatoxin contamination of maize is a leading threat to health in Guatemala. This contamination is the result of infection from Aspergillus flavus and has been effectively reduced in other countries through application of nonaflatoxigenic, indigenous strains of A. flavus. We collected 82 maize samples from throughout Guatemala in two years and isolated 272 A. flavus from these samples, including 126 unique genotypes. We provide here a phenotypic and simple sequence repeat (SSR)-based genotypic description of these isolates, as well as an analysis of the diversity of this population. High levels of genetic diversity were observed with the nonaflatoxigenic isolates in this study, but this information contributes to the development of indigenous aflatoxin biocontrol products.

Study of mercury resistance and Fourier transform infrared spectroscopy-based metabolic profiling of a potent Bacillus tropicus strain from forest soil.

Mercury (Hg) is a highly toxic heavy metal and Hg-resistant indigenous bacterial isolates may offer a green and cost-effective bioremediation strategy to counter Hg contamination. In this study, a potent Hg-resistant bacterium was isolated from the forest soil of a bird sanctuary. Identification using matrix-assisted laser desorption ionization-time of flight mass spectrometry depicted the isolate as a strain of Bacillus tropicus, validated by morphological, biochemical, and molecular studies. The isolate demonstrated biological Hg removal efficiency and capacity of 50.67% and 19.76 mg g-1 , respectively. The plasmid borne resistance determinant, merA, encoding mercuric reductase, was detected in the bacterium endowing it with effective Hg volatilization and resistance capability. A Fourier-transform infrared spectroscopic comparative metabolic profiling revealed the involvement of various functional groups like -COOH, -CH2 , -OH, PO4 - and so on, resulting in differential spectral patterns of the bacterium both in control and Hg-exposed situations. A temporal variance in metabolic signature was also observed during the early and mid-log phase of growth in the presence of Hg. The bacterium described in this study is the first indigenous Hg-resistant strain isolated from the Uttar Dinajpur region, which could be further explored and exploited as a potent bioresource for Hg remediation.

Isolation and characterization of potential indigenous bacteria from the former bauxite mining area for heavy metal reduction

Abstract. Amelia T, Liliasari, Kusnadi, Aditiawati P. 2023. Isolation and characterization of potential indigenous bacteria from the former bauxite mining area for heavy metal reduction. Biodiversitas 24: 5096-5104. This study aimed to isolate, identify, and characterize some indigenous bacterial strains from the former bauxite mining area of Tanjungpinang, Bintan Island, Indonesia. Furthermore, this study focused on evaluating the potential of these bacteria for reducing the heavy metals lead (Pb) and chromium (Cr). The measurements of heavy metal concentrations at four sampling points, collection of soil samples as a bacteria source, and laboratory assessments for bio-removal capabilities were all conducted. Screening experiments were performed to identify bacterial strains resistant to heavy metal, using basic growth media such as Nutrient Agar (NA) and Nutrient Broth (NB) enriched with 100 ppm Pb and Cr metals. The reduction of heavy metal was analyzed with atomic absorption spectrophotometry (AAS), while the bacteria species were determined using MALDI TOF-MS. A modified version of the Kirby Bauer method was employed for toxicity reduction testing. Two bacterial strains were identified as Pb and Cr reducers and demonstrated resistance to both metals. Based on a 99.9% similarity value, the isolates were identified as Bacillus altitudinis (Isolate A) and Klebsiella pneumoniae (Isolate B), reducing Pb by approximately 72.7% and 34.5%, and Cr by 87.4% and 86.2%, respectively. The results indicated reduced toxicity in the metal-enriched media, with bacterial growth following three hours of incubation but no toxicity after 21 hours.

Genotype by Environment Interactions (G*E) of Chickens Tested in Ethiopia Using Body Weight as a Performance Trait.

Ethiopia is a developing nation that could highly benefit from securing food via improved smallholder poultry farming. To support farmer and breeding decisions regarding which chicken strain to use in which Ethiopian environment, G*E analyses for body weight (BW) of growing male and female chickens were conducted. Research questions were (1) if a G*E is present for BW and (2) which strain performs best in which environment in terms of predicted BW. Analyses were performed using predicted BW at four different ages (90, 120, 150, and 180 days) of five strains (Horro, Koekoek, Kuroiler, Sasso-Rhode Island Red (S-RIR), and Sasso) tested in five Ethiopian regions (Addis Ababa, Amhara, Oromia, South Region, and Tigray) that are part of three Agro-Ecological Zones (AEZ) (cool humid, cool sub-humid, and warm semi-arid). The indigenous Horro strain was used as a control group to compare four other introduced tropically adapted strains. The dataset consisted of 999 female and 989 male farm-average BW measurements. G*E was strongly present (p < 0.001) for all combinations of strain and region analyzed. In line with previous research, Sasso was shown to have the highest predicted BW, especially at an early age, followed by Kuroiler. Horro had the lowest predicted BW at most ages and in most regions, potentially due to its young breeding program. The highest predicted BW were observed in Tigray, Oromia, and Amhara regions, which are in the main part of the cool sub-humid AEZ.

Wine aroma modification by Hanseniaspora uvarum: A multiple-step strategy for screening potential mixed starters

Hanseniaspora uvarum is a prevalent yeast species in vineyards. However, its application in grape wine fermentation remains limited. This study used culture-dependent and -independent approaches to investigate the dynamics of H. uvarum during the spontaneous fermentation of Cabernet Sauvignon grapes. The results revealed that H. uvarum constituted 77.49 % of the non-Saccharomyces yeast population during fermentation. An indigenous strain, QTX-C10, was isolated from the 148 H. uvarum strains using a multistep screening strategy. The 1:1 co-inoculation of QTX-C10 with Saccharomyces cerevisiae proved to be an optimal strategy for mixed fermentation, resulting in a 48.54 %–59.55 % increase in ethyl esters in Cabernet Sauvignon wine and a 96.94 %–110.92 % increase in Chardonnay wine. Furthermore, this approach reduced the acetic acid levels by 12.50 %–17.07 % for Cabernet Sauvignon wine and 10.81 %–17.78 % for Chardonnay wine. Additionally, increased ethyl ester content may enhance the tropical fruit flavor of Cabernet Sauvignon wines.