Depletion of the fossil fuels together with an increase in energy demand is considered as a serious threat to the world. Furthermore, fuel versus food dilemma plays an important role in search of ...sustainable non-edible feedstocks for production of biofuels. Liquid biofuels such as bioethanol can pave way for a cleaner earth together with less dependency on fossil fuels. Empty fruit bunches (EFBs) is one of the potential biomass wastes, which can be utilized as a raw material for bioethanol production. The high availability of EFBs as a biowaste in Malaysia can endorse the concept of waste-to-wealth that had been long dreamed since late 1990, where unwanted wastes are converted into valuable energy. The three important steps in bioethanol production from EFBs, i.e. pretreatment, hydrolysis, and fermentation are discussed in this paper. This review paper highlights some available literature and detailed information regarding the EFBs as a potential feedstock for bioethanol production in Malaysia. An environmental-friendly bioenergy and zero waste can be anticipated in Malaysia which in turn promotes an economically sustainable bioethanol production. This review is vital as it explores the EFBs potential as a promising feedstock for bioethanol which can be implemented for future commercial purpose.
•Overview of EFBs as a feedstock for bioethanol in Malaysia.•Bioconversion process in bioethanol production.•EFBs bioconversion process analysis.
The current issues of the depletion of fossil fuels reserve and environmental changes have increased the concern for the hunt of sustainable renewable energy for the future generations. Biofuels ...emerged as a promising viable alternative to replace the existing fossil fuels. Among these, bioethanol outstands due to its ability to substitute gasoline. However, the major challenge in bioethanol industry is the need to discover a suitable feedstock together with an environmentally friendly approach and an economically feasible process of production. The first generation and second generation bioethanol appeared unsustainable due to its impact on food security as well as inflated production process. These problems and concerns have directed the search for the third generation bioethanol (TGB) feedstock from marine algae. The integration of algae (microalgae and macroalgae) as a sustainable feedstock for bioethanol has gained worldwide attention in terms of food security and environmental impact. The research on algal utilization in bioethanol has increased in recent years and is expected to become the major drives in bioethanol industry. Therefore, the potential and prospects of the third generation bioethanol feedstock are being highlighted in this review. An insight into the current hydrolysis and fermentation technologies on algal conversion together with the economics and viability of the process are also accounted. This review can be crucial in providing ideas for the future studies that can be implemented in the commercialization of bioethanol from the third generation feedstock.
Bioethanol has been identified as the mostly used biofuel worldwide since it significantly contributes to the reduction of crude oil consumption and environmental pollution. It can be produced from ...various types of feedstocks such as sucrose, starch, lignocellulosic and algal biomass through fermentation process by microorganisms. Compared to other types of microoganisms, yeasts especially
is the common microbes employed in ethanol production due to its high ethanol productivity, high ethanol tolerance and ability of fermenting wide range of sugars. However, there are some challenges in yeast fermentation which inhibit ethanol production such as high temperature, high ethanol concentration and the ability to ferment pentose sugars. Various types of yeast strains have been used in fermentation for ethanol production including hybrid, recombinant and wild-type yeasts. Yeasts can directly ferment simple sugars into ethanol while other type of feedstocks must be converted to fermentable sugars before it can be fermented to ethanol. The common processes involves in ethanol production are pretreatment, hydrolysis and fermentation. Production of bioethanol during fermentation depends on several factors such as temperature, sugar concentration, pH, fermentation time, agitation rate, and inoculum size. The efficiency and productivity of ethanol can be enhanced by immobilizing the yeast cells. This review highlights the different types of yeast strains, fermentation process, factors affecting bioethanol production and immobilization of yeasts for better bioethanol production.
A simultaneous saccharification and fermentation (SSF) optimization process was carried out on pretreated empty fruit bunches (EFBs) by employing the Response Surface Methodology (RSM). EFBs were ...treated using sequential acid-alkali pretreatment and analyzed physically by a scanning electron microscope (SEM). The findings revealed that the pretreatment had changed the morphology and the EFBs’ structure. Then, the optimum combination of enzymes and microbes for bioethanol production was screened. Results showed that the combination of S. cerevisiae and T. harzianum and enzymes (cellulase and β-glucosidase) produced the highest bioethanol concentration with 11.76 g/L and a bioethanol yield of 0.29 g/g EFB using 4% (w/v) treated EFBs at 30 °C for 72 h. Next, the central composite design (CCD) of RSM was employed to optimize the SSF parameters of fermentation time, temperature, pH, and inoculum concentration for higher yield. The analysis of optimization by CCD predicted that 9.72 g/L of bioethanol (0.46 g/g ethanol yield, 90.63% conversion efficiency) could be obtained at 72 h, 30 °C, pH 4.8, and 6.79% (v/v) of inoculum concentration using 2% (w/v) treated EFBs. Results showed that the fermentation process conducted using the optimized conditions produced 9.65 g/L of bioethanol, 0.46 g/g ethanol yield, and 89.56% conversion efficiency, which was in close proximity to the predicted CCD model.
Taraxerol is a pentacyclic triterpenoid that is actively produced by some higher plants as part of a defense mechanism. The biosynthesis of taraxerol in plants occurs through the mevalonate pathway ...in the cytosol, in which dimethylallyl diphosphate (DMAPP) and isopentyl pyrophosphate (IPP) are first produced, followed by squalene. Squalene is the primary precursor for the synthesis of triterpenoids, including taraxerol, β-amyrin, and lupeol, which are catalyzed by taraxerol synthase. Taraxerol has been extensively investigated for its medicinal and pharmacological properties, and various biotechnological approaches have been established to produce this compound using in vitro techniques. This review provides an in-depth summary of the hypothesized taraxerol biosynthetic pathway, the medicinal properties of taraxerol, and recent developments on tissue culture for the in vitro production of taraxerol.
Macodes limii J.J. Wood & A.L. Lamb is an endemic jewel orchid of Sabah in Borneo. The species has unique characteristic with high potential to be commercialized as ornamental plant. However, it was ...understudied due to its scarcity in nature, which can only be found at certain area in Sabah with ultramafic soil. To understand the reproduction biology of this species, the present study was conducted to document the developmental stages of flower and capsule to determine the right harvesting time for further use in seed germination study. Macodes limii was collected from its natural habitat and cultivated ex situ throughout this study. Flower development was recorded starting from inflorescence initiation until full bloom, which took over 54 days to complete. Flower was artificially pollinated, and capsule was produced within 22 days, and harvesting was performed prior to dehiscence. Seeds were aseptically cultured on half-strength Murashige and Skoog medium + 3% (w/v) sucrose, and 29% of seeds were successfully germinated after 24 weeks under continuous dark condition. The current findings are beneficial as a reference to support the conservation efforts of this endemic species.
Response Surface Methodology (RSM) based on Central Composite Design (CCD) was employed to optimize the conditions of enzymatic hydrolysis and fermentation of the seaweed Eucheuma cottonii. The ...significant influence of cellulose loading, enzyme loading and incubation time in enzymatic hydrolysis that has been screened by Plackett-Burman Design (PBD) was optimized using CCD. The optimum glucose concentration of 24.24 g/L (81% glucose yield) was obtained at 3% (v/v) of cellulose loading, 4% (v/v) of enzyme loading and 54 h incubation time. Subsequently, PBD analysis showed the significant effects of inoculum concentration, pH, temperature and time on fermentation process. Further optimization study by CCD revealed that 12% (v/v) of inoculum concentration, pH 5.2, 32 °C and 72 h of fermentation time enhanced the bioethanol production up to 9.77 g/L with the yield of 0.40 g/g and 78% conversion efficiency. Thus, the RSM based optimization of bioethanol from Eucheuma cottonii showed satisfactory results in this research. In short, it can be concluded that this optimization approach will serve as a good foundation for the realization of a consistent bioethanol production in the future.
•Eucheuma cottonii seaweed was employed as the main feedstock for bioethanol production.•Enzymatic hydrolysis and fermentation were the main conversion technologies utilized.•Response Surface Methodology was used to optimize the enzymatic hydrolysis and fermentation for bioethanol production.
In vitro seed germination has been proven to be the most efficient technique to propagate orchid. The application of this aseptic technique has contributed to conservation of many endangered orchid ...species. In this study, undehisced capsules of Vanda helvola Blume were collected from Orchid Conservation Centre in Lagud Sebrang Agriculture Park, after 120 days from hand pollination and aseptically cultured on three types of basal media such as Murashige and Skoog (MS), Knudson C (KC) and Vacin and Went (VW). After 90 days of culture, 66.40 ± 4.14% of seeds successfully germinated on KC medium. The effect of organic additives such as tomato juice, coconut water, peptone and yeast extract at different level of concentrations in KC basal medium were also tested on seed germination and seedling development of this native orchid. After 90 days of culture, over 90% of seeds were tremendously germinated on KC medium supplemented with 10% or 15% (v/v) of tomato juice. The incorporation of peptone at 0.1% (w/v) in KC basal media promoted rapid development of protocorm to seedling. Seedlings on this treatment produced an average of three leaves and two roots after 90 days of culture and were successfully acclimatized.
Hospital-acquired infections (HAIs) have continually affected the quality of hospital care. Despite medical interventions by healthcare personnel and improved healthcare facilities, the rates of ...morbidity and mortality due to HAIs is increasing. However, a systematic review of HAIs is lacking. Therefore, this systematic review aims to determine the prevalence rate, types, as well as causes of HAIs in Southeast Asian countries.
A systematic literature search was conducted on PubMed, Cochrane library, World Health Organization database-Index Medicus for South-East Asia Region (WHO-IMSEAR), and Google Scholar databases. The search period was from 1st January 1990 until 12th May 2022. The prevalence of HAIs and subgroups were calculated using MetaXL software.
The database search retrieved 3879 non-duplicate articles. After applying exclusion criteria, 31 articles with a total number of 47666 subjects were included and a total of 7658 cases of HAIs were recorded. The overall prevalence of HAIs in Southeast Asia was 21.6 % (95% CI: 15.5 - 29.1%) with heterogeneity statistics of I2 = 100%. Indonesia had the highest prevalence rate of 30.4% whereas Singapore had the lowest prevalence rate at 8.4%.
This study revealed that the overall prevalence of HAIs was relatively high and the prevalence rate of each country was associated with socioeconomic status. Measures should be taken to examine and control the rates of HAIs in countries with high HAI prevalence.
In vitro seed germination has been proven to be the most efficient technique to propagate orchid. The application of this aseptic technique has contributed to conservation of many endangered orchid ...species. In this study, undehisced capsules of Vanda helvola Blume were collected from Orchid Conservation Centre in Lagud Sebrang Agriculture Park, after 120 days from hand pollination and aseptically cultured on three types of basal media such as Murashige and Skoog (MS), Knudson C (KC) and Vacin and Went (VW). After 90 days of culture, 66.40 ± 4.14% of seeds successfully germinated on KC medium. The effect of organic additives such as tomato juice, coconut water, peptone and yeast extract at different level of concentrations in KC basal medium were also tested on seed germination and seedling development of this native orchid. After 90 days of culture, over 90% of seeds were tremendously germinated on KC medium supplemented with 10% or 15% (v/v) of tomato juice. The incorporation of peptone at 0.1% (w/v) in KC basal media promoted rapid development of protocorm to seedling. Seedlings on this treatment produced an average of three leaves and two roots after 90 days of culture and were successfully acclimatized.
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