Biovanillin production from lemongrass leaves hydrolysates by Phanerochaete chrysosporium ATCC 24725 in batch culture

Biovanillin is one of fungi secondary metabolites, that is widely used as aromatic and flavour compound with high fiscal value. The use of vanillin as flavour for various products is its foremost application in food industries. The global market demand for natural vanillin as flavour stands for less than one percent (1%) of its market demand annually. However, most of the flavour compounds are normally obtained through the process of chemical synthesis, which could cause health problem and environmental hitches. Demand for natural and healthy products coupled with the fact that acid ferulic (FA) extracted from plant materials can be a precursor for biovanilin production makes it relatively inexpensive as a natural product. The research was aimed to extract FA from lemongrass leaves (LGL), which was used as precursor for one-step biovanillin production by Phanerochaete chrysosporium (ATCC 24725) in batch culture. Initially, optimization of the LGL pretreatment practices using liquid hot water with sodium bisulfite (0.5% w/v) towards the release of the FA was investigated with central composite design (CCD). The optimized results produced 0.750 g/L as the highest FA released from the lemongrass leaves hydrolysates (LLH). Considerable alterations of the major LGL contents were observed during the pretreatment process, which increased the cellulose content by 39%. The Fourier transform infrared (FTIR) and field emission scanning electron microscopic (FESEM) analyses confirmed that the lignin which serves as the shielding layer from the LGL components became fragmented, thus decreasing the lignin content by 46%. The total reducing sugar production with enzymatic saccharification using enzymes cocktail (celluclast and viscozyme, 1 % v/v each) improved by up to 8.4-folds as compared to the direct enzymatic saccharification without removing the LGL extracts. Screening of significant factors for biovanillin production using 2-level Factorial Design showed that the biovanillin production processes was affected by the interactive effects of initial FA concentration, incubation temperature, incubation time and initial pH. The highest biovanillin production (0.093 g/L with molar yield 23 %) in shake flasks using the CCD was determined with FA (0.5 g/L), temperature (35 °C), time (72 h), and initial pH (6.0). Application of both pH and dissolved oxygen control strategies in 2 litre stirred tank bioreactor had increased the biovanillin production by 1.41 and 1.53-folds as compared to the optimized experiment using the shake flasks. The evaluation of kinetics from the two-phase pH control strategy demonstrated the performance of P. chrysosporium with the highest specific growth rate (µ) of 0.056 h-1, with an increase in the yield coefficient of biomass formation Yx/s (0.5191 g/g) and maximum cell concentration Xmax (13.0 g/L) by 1.03 and 1.05-folds as compared to one-phase of pH control, respectively. Performance of the kinetics using two-phase dissolved oxygen (DO) control strategy has shown that 80 % saturations of DO during active growth phase with 40 % saturations during production phase were highly essential for enhancement of biovanillin production from LLH by P. chrysosporium using 2 litre stirred tank bioreactor. LGL residue which contained FA can be used as a precursor to produce biovanillin by natural means via one-step bioconversion process with P. chrysosporium in batch culture using 2 litre stirred tank bioreactors

Optimum utilization of Clostridia species towards biofuel production

Abstract Global increasing stipulates for the production of renewable fuels due to massive utilization of readily available fossil fuel, more interests in microbial production of biofuels are generated. This opened great opportunities to the biologists, because anaerobic bacteria particularly Clostridium species are capable of converting carbohydrates into a variety of solvents such as acetone, butanol, ethanol and more the like. The review provided ample sources of information with regards to the potentialities of Clostridium species towards production of biofuels. The classification of Clostridium species into pathogenic and non-pathogenic, and those capable of biofuel production has been summarized. Typical metabolic processes responsible for transforming biomass into various biofuels have been highlighted. Utilization of agricultural wastes as substrates towards biofuel production was equally highlighted. Various carbon sources and some Clostridium species exploited for biofuel production were summarized. The review also provided some of the factors that influenced the biofuel production

Improvement of biovanillin production with two-stage pH control strategy from lemongrass leaves hydrolysates using Phanerochaete chrysosporium ATCC 24725 in batch culture

The biovanillin production was influenced by varying the culture pH via single control strategy conducted by separate experiments during the fermentation processes. Highest biovanillin production (124 mg/L) with 32% molar yield at culture pH 6.0 from the one-stage control method was observed. Specific growth rates (µ) of the Phanerochaete chrysosporium and biovanillin production decreased by decreasing the culture pH from 6.0 to 3.5, which indicated that lower culture pH was not adequately apposite for biovanillin production using Phanerochaete chrysosporium in a 2-L stirred tank bioreactor. The development of two-stage control strategies had improved the biovanillin production (131 mg/L) and cell concentration (13.0 g/L) by about 6 and 5%, respectively. Therefore, the most influential control strategy for higher biovanillin production was discovered not to control the culture pH of the fermentation during active growth phase of the Phanerochaete chrysosporium, while the production phase should be controlled at pH 6.0

Emergence and spread of two SARS-CoV-2 variants of interest in Nigeria.

Identifying the dissemination patterns and impacts of a virus of economic or health importance during a pandemic is crucial, as it informs the public on policies for containment in order to reduce the spread of the virus. In this study, we integrated genomic and travel data to investigate the emergence and spread of the SARS-CoV-2 B.1.1.318 and B.1.525 (Eta) variants of interest in Nigeria and the wider Africa region. By integrating travel data and phylogeographic reconstructions, we find that these two variants that arose during the second wave in Nigeria emerged from within Africa, with the B.1.525 from Nigeria, and then spread to other parts of the world. Data from this study show how regional connectivity of Nigeria drove the spread of these variants of interest to surrounding countries and those connected by air-traffic. Our findings demonstrate the power of genomic analysis when combined with mobility and epidemiological data to identify the drivers of transmission, as bidirectional transmission within and between African nations are grossly underestimated as seen in our import risk index estimates

The evolving SARS-CoV-2 epidemic in Africa: Insights from rapidly expanding genomic surveillance

INTRODUCTION Investment in Africa over the past year with regard to severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) sequencing has led to a massive increase in the number of sequences, which, to date, exceeds 100,000 sequences generated to track the pandemic on the continent. These sequences have profoundly affected how public health officials in Africa have navigated the COVID-19 pandemic. RATIONALE We demonstrate how the first 100,000 SARS-CoV-2 sequences from Africa have helped monitor the epidemic on the continent, how genomic surveillance expanded over the course of the pandemic, and how we adapted our sequencing methods to deal with an evolving virus. Finally, we also examine how viral lineages have spread across the continent in a phylogeographic framework to gain insights into the underlying temporal and spatial transmission dynamics for several variants of concern (VOCs). RESULTS Our results indicate that the number of countries in Africa that can sequence the virus within their own borders is growing and that this is coupled with a shorter turnaround time from the time of sampling to sequence submission. Ongoing evolution necessitated the continual updating of primer sets, and, as a result, eight primer sets were designed in tandem with viral evolution and used to ensure effective sequencing of the virus. The pandemic unfolded through multiple waves of infection that were each driven by distinct genetic lineages, with B.1-like ancestral strains associated with the first pandemic wave of infections in 2020. Successive waves on the continent were fueled by different VOCs, with Alpha and Beta cocirculating in distinct spatial patterns during the second wave and Delta and Omicron affecting the whole continent during the third and fourth waves, respectively. Phylogeographic reconstruction points toward distinct differences in viral importation and exportation patterns associated with the Alpha, Beta, Delta, and Omicron variants and subvariants, when considering both Africa versus the rest of the world and viral dissemination within the continent. Our epidemiological and phylogenetic inferences therefore underscore the heterogeneous nature of the pandemic on the continent and highlight key insights and challenges, for instance, recognizing the limitations of low testing proportions. We also highlight the early warning capacity that genomic surveillance in Africa has had for the rest of the world with the detection of new lineages and variants, the most recent being the characterization of various Omicron subvariants. CONCLUSION Sustained investment for diagnostics and genomic surveillance in Africa is needed as the virus continues to evolve. This is important not only to help combat SARS-CoV-2 on the continent but also because it can be used as a platform to help address the many emerging and reemerging infectious disease threats in Africa. In particular, capacity building for local sequencing within countries or within the continent should be prioritized because this is generally associated with shorter turnaround times, providing the most benefit to local public health authorities tasked with pandemic response and mitigation and allowing for the fastest reaction to localized outbreaks. These investments are crucial for pandemic preparedness and response and will serve the health of the continent well into the 21st century

Optimization of biobutanol production by clostridium species upm-a1 with liquid central composite design (ccd)

Optimization of biobutanol production by Clostridium species UPM-A1 was conducted using Central Composite Design (CCD) with liquid pineapple waste as carbon source. The Design Expert® Software (State-Ease Inc., 2021 Ease Hennepin Ave, Suite 191, Minneapolis, MN, 55413) Version 6.0.4 was employed for generating the experimental design which consisted of three significant parameters, including temperature, yeast extract, and pH. The design consisted of twenty different experiments including six replicates at central points. The experiments were conducted in accordance with the conditions provided by the software, during which highest biobutanol production was attained at run three with temperature 42.50°C, yeast extract 2.14g/L, pH 5.5, and a total biobutanol concentration value of 0.441 g/L. Then, a model was generated to see the effects of the variables towards the biobutanol produced. Furthermore, the software suggested optimum value for each parameter as temperature 49.35°C, yeast extract 1.80 g/L, and pH 4 with a biobutanol concentration of 0.405 g/L. A laboratory experiment was conducted to test the predicted variables and eventually 0.417 g/L of biobutanol concentrations was achieved, which is slightly higher than the predicted values. Moreover, growth kinetics of the bacteria towards both solvents (biobutanol, acetone, and ethanol) and acids (acetic acid and butyric acid) production under the optimized conditions was conducted and found acetic acid with the highest yield (Y p/s) value of 15.26 g/g with maximum productivity of 0.23g/L/h, while biobutanol has the lowest yield (Y p/s) value of 1.29 g/g with maximum productivity of 0.01g/L/h. The specific growth rate (µ) and doubling time (td) were found as 0.021h-1 and 33h respectively. The research concluded that Central Composite Design (CCD) is a handy and promising approach for variable optimization towards biobutanol production. However, due to the kinetics evaluated results, the bacterial strain is not apposite for biobutanol production. Nevertheless, it could be used for acetic acid production

Physicochemical and enzymatic saccharification of lemongrass leaves for reducing sugar production

Reducing sugar was found to be embedded within cellulose from the lignin-hemicellulose matrix of the plant materials, which requires certain level of pretreatments before it could be extracted out from the carbohydrate matrices. Pretreatment processes of the lemongrass leaves, toward production of total reducing sugars, were performed by physicochemical pretreatment, enzymes cocktail, as well as enzymatic saccharification. The total reducing sugar (18.34 g/L) was best determined with the combination of the enzymes cocktail (1:1 % v/v), agitation speed (150 rpm), incubation temperature (55 °C) and incubation time (7 days). This result was discovered higher with 3.3 and 8.4-folds when compared to the experiments using physicochemical pretreatment and direct enzymatic saccharification, respectively. However, from the application of single enzyme for the saccharification, celluclast was the most efficient which produced reducing sugar (10.62 g/L), as opposed to using viscozyme (7.43 g/L) with 1.4-folds. The efficiency of the lemongrass leaves pretreatment leading to the higher production of the reducing sugar was confirmed using field emission scanning electron microscope. The research has provided a bottom-up method towards reducing the quantity of lignocellulosic wastes from environments for valuable products

Rice second florigen is crucial for expansion of its’ cultivation areas: A Bioinformatics

Flowering state is an important agronomic trait in determining the plant cropping season and best ecological examples between plant and its existing ecosystem. Rice is a model plant for molecular studies and pertinent for flowering development analysis. Rice Flowering Locus T1 (RFT1) is the second rice florigen which promotes flowering under long-day (LD) condition. This study investigates the correlation between RFT1 gene established accessions towards an expansion of rice cultivation areas in Asia using bioinformatics tools. Fourteen (14) different RFT1 accessions were collected including 9 indica and 5 japonica, and analyzed for molecular evolution. Also, the protein 3-dimensional (3D) structure were predicted and validated. The genes appeared to be highly conserved and functional across the diverse accessions. Cultivars from the two sub-species form a separate sub-group except for Koshihikari, Akamai and Nara aswari which form a major group, while Basmati370 was in the same clade with japonica cultivars. The 3D model indicated that the protein accessions has slight differences and VERIFY 3D model refinement has the best stereochemistry score at 99.38. The study clarified on the cultivars’ evolutionary relationships and suggested that diverse functional RFT1 variants is crucial for expansion of rice cultivation areas.Keyword: Rice, RFT1 gene, Accessions, Phylogenetic tree and 3D mode

Optimization of microwave pre-treatment conditions for maximum lignin recovery from rice husk using central composite design (CCD) by response surface methodology (RSM)

Response surface methodology based on the central composite design (CCD) was applied to investigate the optimum conditions for lignin recovery from rice husk using microwave pre-treatment. Three operating variables namely microwave irradiation time (min), solid loading (%) and microwave power (Watt), with a total of 20 experiment conditions were conducted to optimize the interaction effects of these variables. The results reported that the second-order model was sufficient for all the independent variables on the response with R2 = 0.9861. Response Surface Methodology predicted a maximum lignin recovery of 34.9076% at optimum conditions for microwave irradiation time, solid loading and microwave power were 16.57 min, 9.66%, and 664 Watt respectively. An experiment was run at the optimal condition and lignin recovery of 33.1667% was obtained. The predicted result was thus experimentally verified. The obtained lignin was characterized by Fourier Transform Infrared Spectroscopy (FTIR), Hydrogen Nuclear Magnetic Resonance (1H NMR) and Carbon Nuclear Magnetic Resonance (13C NMR). The lignin produced from microwave pretreatment showed the presence of varieties of functional groups and potentially used for future applications

Biovanillin: production concepts and prevention of side product formation

Application of biotechnological tools as an imminent basis for biovanillin production was established promising using microbes via utilization of readily available agro-based supplies as precursors, and the process was universally accepted as natural. However, the production process was confronted with certain bottlenecks including undesired product formation, ineffective flow of metabolism, product toxicity, and further product degradation by the microbes, which could result to the dwindling of biovanillin concentration within the process. This review paper outlines the various routes and strategies to overcome these setbacks using fed-batch fermentation culture mode with adsorbent resins, activated carbon, and simply metabolized carbon sources and enzyme inducers like cellobiose and maltose. The review aims to provide ample information for diverse utilization of microorganisms like fungi, bacteria, and yeast with diverse biotechnological approaches and metabolic pathways using various precursors such as ferulic acid, isoeugenol, and eugenol, which could be extracted from readily available and cheaper agro-based materials like maize bran, maize stalk, sugar beet pulp, wheat bran, and rice bran oil for biovanillin transformation. The review could equally help researchers and biotechnology industry to explore the optimization process of the whole systems of biovanillin production via utilization of production strains with more tolerance to toxic effect of both the precursors and the biovanillin in a bioreactor with fed-batch fermentation culture mode together with adsorbent resins, shorter incubation time, and effective downstream processing with the target of reducing the production cost of the biotechnology-derived biovanillin to gain remarkable and higher economic value against the vanillin obtained by chemical synthesis