Potential and utilization of thermophiles and thermostable enzymes in biorefining

In today's world, there is an increasing trend towards the use of renewable, cheap and readily available biomass in the production of a wide variety of fine and bulk chemicals in different biorefineries. Biorefineries utilize the activities of microbial cells and their enzymes to convert biomass into target products. Many of these processes require enzymes which are operationally stable at high temperature thus allowing e.g. easy mixing, better substrate solubility, high mass transfer rate, and lowered risk of contamination. Thermophiles have often been proposed as sources of industrially relevant thermostable enzymes. Here we discuss existing and potential applications of thermophiles and thermostable enzymes with focus on conversion of carbohydrate containing raw materials. Their importance in biorefineries is explained using examples of lignocellulose and starch conversions to desired products. Strategies that enhance thermostablity of enzymes both in vivo and in vitro are also assessed. Moreover, this review deals with efforts made on developing vectors for expressing recombinant enzymes in thermophilic hosts

Bovine Brucellosis and Its Public Health Significance in Ethiopia

Bovine brucellosis is endemic and widely distributed in Ethiopia. The country has already prioritized top five zoonotic diseases (rabies, anthrax, brucellosis, Rift Valley fever and highly pathogenic avian influenza) in 2019 using reprioritization workshop. So brucellosis is one of the top five neglected zoonotic diseases in the country. According to several studies, the distribution and prevalence of bovine and human brucellosis in Ethiopia varies among regions in terms of animal production and management systems, community living standards and awareness levels. The disease has major zoonotic and economic implications for rural communities, particularly pastoralists. The aim of this article was therefore to review and summarize recent studies (2010–2021) on the prevalence of bovine brucellosis in animals and humans, with reference to Ethiopia. This review describes both bovine and human brucellosis reported from various geographical areas of the country. Reports between the years 2010 and 2021 indicated a prevalence rate between 1.2% and 22.5% at the individual level, and 3.3% and.68.6% at the herd level. However, the human brucellosis seroprevalence rate was 2.15%–48.3% between 2006 and 2021. This increase clearly indicates the expected future threat of this disease in the country. However, control measures and community awareness are lacking. Therefore, actual implementation of prevention and control measures, community awareness, further studies and continual review to provide compiled information for understanding the transmission dynamics of the disease are essential

Comparison of infectivity of Plasmodium vivax to wild-caught and laboratory-adapted (colonized) Anopheles arabiensis mosquitoes in Ethiopia

BACKGROUND: Mosquito-feeding assays that assess transmission of Plasmodium from man-to-mosquito typically use laboratory mosquito colonies. The microbiome and genetic background of local mosquitoes may be different and influence Plasmodium transmission efficiency. In order to interpret transmission studies to the local epidemiology, it is therefore crucial to understand the relationship between infectivity in laboratory-adapted and local mosquitoes. METHODS: We assessed infectivity of Plasmodium vivax-infected patients from Adama, Ethiopia, using laboratory-adapted (colony) and wild-caught (wild) mosquitoes raised from larval collections in paired feeding experiments. Feeding assays used 4-6 day-old female Anopheles arabiensis mosquitoes after starvation for 12 h (colony) and 18 h (wild). Oocyst development was assessed microscopically 7 days post-feeding. Wild mosquitoes were identified morphologically and confirmed by genotyping. Asexual parasites and gametocytes were quantified in donor blood by microscopy. RESULTS: In 36 paired experiments (25 P. vivax infections and 11 co-infections with P. falciparum), feeding efficiency was higher in colony (median: 62.5%; interquartile range, IQR: 47.0-79.0%) compared to wild mosquitoes (median: 27.8%; IQR: 17.0-38.0%; Z = 5.02; P < 0.001). Plasmodium vivax from infectious individuals (51.6%, 16/31) infected a median of 55.0% (IQR: 6.7-85.7%; range: 5.5-96.7%; n = 14) of the colony and 52.7% (IQR: 20.0-80.0%; range: 3.2-95.0%; n = 14) of the wild mosquitoes. A strong association (ρ(16) = 0.819; P < 0.001) was observed between the proportion of infected wild and colony mosquitoes. A positive association was detected between microscopically detected gametocytes and the proportion of infected colony (ρ(31) = 0.452; P = 0.011) and wild (ρ(31) = 0.386; P = 0.032) mosquitoes. CONCLUSIONS: Infectivity assessments with colony and wild mosquitoes yielded similar infection results. This finding supports the use of colony mosquitoes for assessments of the infectious reservoir for malaria in this setting whilst acknowledging the importance of mosquito factors influencing sporogonic development of Plasmodium parasites

Ecology and genomics of an important crop wild relative as a prelude to agricultural innovation

Domesticated species are impacted in unintended ways during domestication and breeding. Changes in the nature and intensity of selection impart genetic drift, reduce diversity, and increase the frequency of deleterious alleles. Such outcomes constrain our ability to expand the cultivation of crops into environments that differ from those under which domestication occurred. We address this need in chickpea, an important pulse legume, by harnessing the diversity of wild crop relatives. We document an extreme domestication-related genetic bottleneck and decipher the genetic history of wild populations. We provide evidence of ancestral adaptations for seed coat color crypsis, estimate the impact of environment on genetic structure and trait values, and demonstrate variation between wild and cultivated accessions for agronomic properties. A resource of genotyped, association mapping progeny functionally links the wild and cultivated gene pools and is an essential resource chickpea for improvement, while our methods inform collection of other wild crop progenitor species

The global burden of cancer attributable to risk factors, 2010-19 : a systematic analysis for the Global Burden of Disease Study 2019

Background Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. Methods The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk-outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. Findings Globally, in 2019, the risk factors included in this analysis accounted for 4.45 million (95% uncertainty interval 4.01-4.94) deaths and 105 million (95.0-116) DALYs for both sexes combined, representing 44.4% (41.3-48.4) of all cancer deaths and 42.0% (39.1-45.6) of all DALYs. There were 2.88 million (2.60-3.18) risk-attributable cancer deaths in males (50.6% [47.8-54.1] of all male cancer deaths) and 1.58 million (1.36-1.84) risk-attributable cancer deaths in females (36.3% [32.5-41.3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20.4% (12.6-28.4) and DALYs by 16.8% (8.8-25.0), with the greatest percentage increase in metabolic risks (34.7% [27.9-42.8] and 33.3% [25.8-42.0]). Interpretation The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden. Copyright (C) 2022 The Author(s). Published by Elsevier Ltd. This is an Open Access article under the CC BY 4.0 license.Peer reviewe

An Alkaline Active Endo-Xylanase from Bacillus halodurans S7:Molecular and Structural Aspects

A strain of an alkaliphilic bacterium Bacillus halodurans was isolated from a water sample in Lake Shalla, a soda lake in the Ethiopian Rift Valley. From the culture of this isolate, B. halodurans S7, a xylanase which is active in a wide range of pH, with an optimum at about 9-9.5 was purified. When assayed at pH 10, the enzyme was optimally active at 70 ?C. The xylanase was free from any associated cellulase activity. The gene encoding this protein was cloned, sequenced and expressed in Escherichia coli. Based on amino acid sequence similarity, the enzyme belongs to the glycoside hydrolase family 10. Multiple sequence alignment revealed the presence of eight distinct conserved regions in the sequences of family 10 xylanases of different origins. Moreover, insert amino acids were identified in sequences of xylanases, which exhibit significant activity at or above pH 9. The crystal structure of the xylanase was determined and was found to be an elliptical eight-fold ?/?-barrel. Unlike most xylanase structures determined so far, the long axis of the barrel is longer in this xylanase. Sequence composition and structural analysis provided insights on possible mechanisms that could render the enzyme active and stable under high pH conditions. Compared to non-alkaline active xylanases, B. halodurans S7 xylanase exhibited higher % composition of arginine, glutamine and histidine. Moreover, the enzyme was found to have excess acidic residues, in particular glutamic acid, on its surface. The excess negative charge on the protein might form a water shield that offers protection in the extreme environment. Compared to other family 10 xylanases for which the structures have been determined, this xylanase has a deeper active site cleft, which might explain its high substrate specificity. The degradation of insoluble xylan, in particular from oat spelts, by the xylanase was not efficient. The hydrolytic efficiency towards this substrate was improved by the fusion of the B. halodurans S7 xylanase with N-terminal carbohydrate binding domains from Thermotoga neapolitana xylanase A. However, the chimeric enzyme was found to be heat labile compared to the native xylanase. The adaptation role of the insert amino acids found in xylanases that exhibit significant activities at elevated pH was investigated by constructing deletion mutants. From the characterization studies of the deletion variant xylanases, it seems that there is no significant shift in the pH and temperature optima of the mutant enzymes. One of the mutants was as active as the wild type xylanase whereas the activity of the other two mutants was low and the fourth mutant had no detectable activity

Enzymatic monitoring of lignin and lignin derivatives biooxidation.

Lignin oxidation was enzymatically monitored by measuring methanol released during the reaction. The methanol was oxidized to formaldehyde and hydrogen peroxide, and the latter used to oxidize ABTS to a product measured spectrophotometrically. The efficiency was comparable to the commonly used gas chromatography method. The assay was fast and inexpensive