This study examined the use of Saccharomyces cerevisiae and Pseudomonas aeruginosa as a mixed microbial culture to enhance bioethanol production from sugarcane bagasse (SCB). Traditional single-culture fermentation is limited by substrate utilization and environmental fluctuations, whereas mixed-culture fermentation exploits the complementary metabolic activities of both microorganisms. Sugarcane bagasse was pretreated with 2% v/v sulfuric acid (H2SO4), followed by enzymatic hydrolysis and separate hydrolysis and fermentation (SHF). The optimal cellulase:beta-glucosidase ratio (1:4) produced the highest glucose concentration (8.28 +/- 0.06 g L-1). Response surface methodology (RSM) predicted a bioethanol yield of 3.48 g L-1 (0.17 g/g SCB-to-ethanol) with 82.4% conversion efficiency. Experimental validation using the S. cerevisiae-P. aeruginosa system yielded 3.43 g L-1 of bioethanol (0.172 g/g SCB-to-ethanol) and an 81.23% conversion efficiency under the optimized conditions (7.36% (v/v) total inoculum, 72 h, 30 degrees C, pH 4.8). This study demonstrates the advantages of mixed-culture fermentation, showing improved efficiency and potential cost reductions for large-scale bioethanol production.

The production of lactic acid (LA), a key precursor for poly-lactic acid (PLA) as a sustainable alternative to conventional plastics, is gaining significant industrial and environmental attention. This study evaluates the potential of utilizing oil palm empty fruit bunches (EFBs), an abundant lignocellulosic agro-industrial waste, for lactic acid production through fermentation. A separate hydrolysis and fermentation (SHF) process was employed using Lactobacillus acidophilus A1 ATCC 4356, chosen for its ability to optimize enzymatic hydrolysis and fermentation independently, thereby enhancing process efficiency. Fermentation conditions, including inoculum size, temperature and time, were systematically optimized to achieve maximum lactic acid yield. Under optimal conditions (35 °C, 10

Currently, non-renewable fossil fuels provide the majority of the world's energy. Biofuel such as bioethanol is an important alternative and substitute energy source which can be used to cater for the energy requirement in the world. This chapter focuses on producing bioethanol from lignocellulosic biomass due to its abundance in nature. Up-to-date information on recent developments and research on bioethanol is completed to investigate the issues in present literature studies regarding bioethanol production. The methods of the bioethanol conversion process are explored to improve the performance and maximize the yields. Different ranges of parameters are studied to determine the optimum value of each parameter in producing a higher yield of bioethanol. However, further research on the bioethanol technology conversion process is vital to ensure the bioprocess used in producing bioethanol becomes commercially and economically feasible.

In this article, the latest discoveries in the development of biosensors based on enzyme inhibition are reviewed. Due to their excellent selectivity and sensitivity, they represent a significant alternative method to conventional analytical methods; which is a method of analysis that only relies on the generation of instrumentation data without any preliminary screening. Basically, biosensors are able to convert biological activity into a quantifiable signal. These enzyme inhibition-based biosensors have a wide range of applications in the fields of environmental safety, food safety, and clinical analysis since toxic substances containing heavy metals and pesticides are the most effective inhibitors of enzymes. This paper is aimed at exploring the methods used and the sensitivity to various inhibitors for biosensors based on the inhibition of enzymes such as glucose oxidase, urease, tyrosinase, cholinesterase, and other enzymes.

In this article, the latest discoveries in the development of biosensors based on enzyme inhibition are reviewed. Due to their excellent selectivity and sensitivity, they represent a significant alternative method to conventional analytical methods; which is a method of analysis that only relies on the generation of instrumentation data without any preliminary screening. Basically, biosensors are able to convert biological activity into a quantifiable signal. These enzyme inhibition -based biosensors have a wide range of applications in the fields of environmental safety, food safety, and clinical analysis since toxic substances containing heavy metals and pesticides are the most effective inhibitors of enzymes. This paper is aimed at exploring the methods used and the sensitivity to various inhibitors for biosensors based on the inhibition of enzymes such as glucose oxidase, urease, tyrosinase, cholinesterase, and other enzymes.

Polyhydroxyalkanoates (PHA) are biodegradable bioplastics accumulated in microbial cells which have immense potential to replace the existing non-biodegradable plastics. This study focuses on optimizing Bacillus cereus growth conditions to enhance PHA formation, utilizing the sugarcane bagasse (SCB) as the primary feedstock. The SCB was subjected to enzymatic hydrolysis, resulting in 8.33 mg/g of total sugar production. Subsequently, Bacillus cereus was cultivated and the treated SCB was employed for PHA synthesis. An essential precursor to this synthesis involves an in-depth investigation into the characterization of the PHA produced using Bacillus cereus. A total of 20 experimental runs of different parameter conditions for Bacillus cereus culture to produce PHA were optimized by using the Response Surface Methodology (RSM). At an inoculum size of 8% (v/v), temperature of 25 °C, and incubation time of 48 hours, the highest PHA was produced with 86.4 g/L or 62.1% (w/w). The optimal growth rate of Bacillus cereus was obtained at 7.71% (v/v), 35.1 °C for 48.3 hours. The greatest PHA content and yield were found to be 57.9% (w/w) of PHA accumulation and 90.39 g/L, respectively. The synthesized PHA is characterized by using FTIR, XRD, FESEM-EDX, and soil burial test. From the analysis done, the properties of the produced sample were confirmed as the PHA. The soil burial test observed that the polymer was a PHA with a biodegradability rate of 41.73% in a week. The study successfully optimized the Bacillus cereus culture conditions for PHA production by using sugarcane bagasse hydrolysate at 8% (v/v) as the feedstock.

Acetylcholinesterase (AChE) is a well-known enzyme sensitive to pesticide exposure, but heavy metal sensitivity is rarely reported. Here, AChE extracted from the brain tissue of Diodon hystrix was exploited and used in a fast and economical way to sensitively detect the existence of heavy metals in a water sample. An inhibitive enzyme assay was conducted, and the activity of AChE was found to be sensitive (> 20% inhibition) to sub-million levels of arsenic, cadmium, nickel, and zinc and less sensitive (< 20% inhibition) to copper and lead. While exposure to argentum, cobalt, and chromium shows no significant inhibition, AChE is not sensitive to those metal ions (p < 0.05). Field test work has proved that the assay is suitable for preliminary detecting heavy metal contamination in the river, especially near industrial and mining sites. Secondary validation was performed using ICP-OES to identify and measure the number of elements in the sample and compare them to the inhibition level of AChE activity.

Ethnomedicinal properties of Psidium guajava L. , or also known as guava leaves has been known since years ago. Nowadays, a lot of guava leaves-based products emerge in industries such as tea and cosmetic. The aims of this study are to examine and compare the variation in the phytochemical constituent as well as the antimicrobial efficacy of young and mature leaves extract. Phytochemical analysis shows the presence of phenol, tannin, terpene, saponin, and flavonoid in the mature leaves methanolic extract. A similar result was obtained in the young leaves extract but no saponin was detected. Total phenols content in young and mature leaves were determined at a total of 31.2 mg and 162 mg GA/g. Both leave extract was carried out to determine the antimicrobial properties by tested against two Grampositive bacteria (Staphylococcus aureus and Bacillus cereus) and one gram-negative bacteria (Salmonella enterica) through the disk-diffusion method by employing 40 µL of leaf extract solution per disk. Based on the observation, both young and mature extracts exhibited inhibitory activity (<6.0 mm) against the tested bacteria with different sensitivity. At the concentration of 10 mg/mL, mature leaves extract shows higher efficacy on S. enterica and B. cereus where the inhibitory zone was measured at 9.3 mm and 7.8 mm, respectively, compared to young leaves which is not sensitive to S. aureus but the inhibitory zone on B. cereus around 7.2 mm while S. aureus at 7.2 mm higher than mature leave extract. This can be concluded that the P. guajava mature leave displayed the best to applied as medicinal purposes as its high variety of phytochemical content and high efficacy as antimicrobial activity.

Biodiesel production from Waste Palm Cooking Oil (WPCO) is of interest to substitute fossil derived diesel fuel, due to its renewable nature, cleaner emissions and non-toxic properties. Thus, in this study, biodiesel production through transesterification process was optimized using immobilized lipase from Candida rugosa and WPCO collected from the faculty’s cafeteria as a feedstock. Interaction between five operating factors: molar ratio of ethanol to oil, water content, lipase loading, reaction temperature and time on the biodiesel yield were investigated. It was observed that, with the optimal conditions of 10:1 molar ratio of ethanol to oil, 1 g water, temperature 40 °C, 0.8 g immobilized lipase and 32 h reaction time, a yield of 85.72% of biodiesel could be achieved. Thus, this study shows that WPCO, an environmental waste, can be utilized as a promising feedstock for biodiesel production using environmentally friendly biocatalysts such as immobilized lipase.

Biobutanol has been identified as a promising future biofuel. However, generally the extraction and separation of biobutanol from the fermentation mixture is a costly process. Therefore, the idea of using acetone-butanol-ethanol (ABE) mixture directly as biofuel were proposed to eliminate the recovery process. ABE has been identified as a promising future biofuel. The feedstocks play an important role in the feasibility of ABE as a fuel. Lignocellulosic biomass is seen as a promising feedstock for the production of biofuels. Thus, in this review, ABE biofuel is been summarized from three aspects namely (i) selection of feedstocks, (ii) microbial selection and (iii) hydrolysis, fermentation, and purification techniques. Anaerobic fermentation together with commonly employed recovery processes are discussed in the second part of this review. This review concludes with different challenges and future research in ABE fermentation that can pave the way for future commercialization of this promising biofuel.

A significant concern in generating ecologically friendly plastics has paved a way for use of algae-based green bioplastics as a substitute for conventional plastics. This study signifies the production and characterization of biodegradable algae-based bioplastics using alginate extracted from brown seaweeds of Sargassum sp. found abundantly in coastal waters of Sabah, Malaysia. During the extraction of alginate from Sargassum sp., process variables such as the alkali (Na2CO3) concentration, temperature (°C), and time (hours) were optimized by employing ethanol method of extraction. The maximum yield of alginate (20.85 %) was obtained with the following conditions of 3 % of Na2CO3, at 95 °C and 3 h. Then, the extracted alginate was used to synthesize seven bioplastics with different formulations, one in the absence of invert sugar (green plasticizer) as control while the others were blended with 5 %, 10 % and 15 % of invert sugar (IS) respectively. The synthesized bioplastics were further characterized via mechanical test through tensile-strength (TS) and elongation at break (E) while its degradability was evaluated using soil burial test. The results reveal that bioplastics incorporated with IS enhanced the features of the bioplastics as they were more flexible, unlike the control bioplastics which were brittle. Among the formulations used, the bioplastics that comprised of alginate (Alg) 6 % with 5 % IS exhibited the highest TS and were able to degrade completely within 4 days. Thus, this study brings in an insight into the importance of Sargassum sp. as a potential feedstock for the development of green algae-based bioplastics to counter the plastic pollution problems as it can surpass the sustainability matter and environmental challenges caused by disposal of conventional plastics.

Development in Malaysia is in line with positive economic growth. The situations have led to the improvement of industrial and agricultural activities that produce high-quality products of a global quality, which has a significant impact on the income of the local people. However, the activity also contributed to river pollution, where the industrial and agricultural wastes were discharged to nearby water sources, whether intentionally or not. The residues containing heavy metals are of concern because their concentration can negatively affect the environment. Furthermore, their ability to be treated or remedied is very limited. Biosensor acetylcholine, AChE extracted and purified from Monopterus albus brain, acts as an alternative biosensor to rapidly detect the presence of heavy metals with a simple application. The tests were conducted at ten different location points from the upstream to the downstream of Bentong River and Terengganu River, classified as a Class II river by the Department of Environment Malaysia. Bentong River and Terengganu River showed that five and two samples from different location points were able to inhibit AChE activity by more than 10%, respectively. The three samples with the highest inhibition were selected for the secondary screening through identification and the heavy metal concentrations determination using ICP-OES. All samples showed heavy metals such as copper, nickel, lead, arsenic, silver, chromium, and zinc at different concentrations and synergistically affected AChE activity. The use of AChE as a biosensor is able to detect and characterize pollution levels in both rivers that differ in the level of local development, such as industrial activities and population density.

Dumping of food wastes into the landfill resulted in major environmental pollution. However, attempted had been made to develop these wastes into a new renewable and sustainable energy. Liquid biofuels, bioethanol can be produced from a variety of feedstock including biomass and food crops or wastes. Therefore, in this study, starchy food wastes of bread, rice and potatoes were utilized as a potential feedstock for the bioethanol production. Yeast Saccharomyces cerevisiae was immobilized in 2% calcium alginate beads using entrapment technique. Then, the effect of temperature on bioethanol efficiency was investigated using the immobilized yeasts. From the result, highest fermentation efficiency of 1.24% was obtained at temperature 30°C, 48 h with agitation speed of 150 rpm. However, further research and studies are required in order to optimize the bioethanol production from fermentation process of starchy foodwastes.

Liquid biofuels such as bioethanol is a promising renewable fuel as it can be produced from various biomass wastes as feedstocks. The concept of waste to wealth approach is inevitable for bioethanol production. In Malaysia, banana peels are one of the largest agricultural wastes found in the local market. Thus, in this study, banana peels were used as a feedstock to produce bioethanol through fermentation using immobilized yeast cells. For higher yield of bioethanol, optimization parameters were conducted for both dilute acid hydrolysis and fermentation process. First, the banana peels were sliced and oven-dried at 70°C for 24 h before being ground to fine powder. Then, the samples were subjected to dilute acid hydrolysis. Parameters such as concentration of H 2 SO 4 , temperature and time were optimized during the hydrolysis. Higher amount of reducing sugar was obtained at 0.10 M H 2 SO 4 , at 90°C for 20 min with 5.190 mg/mL, 5.196 mg/mL and 5.306 mg/mL respectively for the hydrolysis process. Yeast Saccharomyces cerevisiae was immobilized using 3% (w/v) of sodium alginate and 2% (w/v) calcium chloride using entrapment technique, in the form of beads. These immobilized beads were added into the fermentation medium together with the optimized pretreated hydrolysate of banana peels. Parameters such as cells loading (weight of beads), pH, temperature and time were also optimized in the fermentation process. From the results, it was found out that the optimized parameters of 9g of cells loading, pH 5, at 30°C for 24 h utilized more sugar during fermentation process based on the absorbance reading.

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.

Underutilized plants are referred to a plant species whose potential is not fully utilized yet and they are usually found abundantly in certain local areas but are globally rare. Sabah is known for high biodiversity and contains many underutilized plants. To our knowledge, this is the first review to provide overview information of the medicinal value and pharmacological properties of underutilized plants in Sabah. Extract and metabolites in different parts of several underutilized plants contain multiple beneficial bioactive compounds and the exploitation of these compounds was supported by additional data that plays various biological activities, including anti-atherosclerotic, anti-cancer antihypercholesterolemic and anti-ulcerogenic. A handful of pharmacological studies on these underutilized plants have conclusively outlined the mode of action in treatment of several diseases and in other health aspects. This paper limits its scope to review and highlight the potential of using underutilized plants in Sabah only which could serve as reliable resource for health product development in pharmaceutical and nutraceutical through continuous discovering of more active and sustainable resources as well as ingredients for food and medicine.

Biofuel production by utilizing yeast during fermentation process is one of the main concern to maximize the ethanol productivity. In this study, a total of 20 soil examples were collected from 4 sampling site around Kota Kinabalu. They were selected due to their potential habitat of yeast S. cerevisiae. The purpose of this study was to isolate and characterize S. cerevisiae from soil for bioethanol production. A total of 6 strains of yeast were isolated with the use of yeast-extract peptone agar medium. The isolated strains were identified by morphological, physiological and molecular characterization, resulting in discovery of the S. cerevisiae from the samples. In physiological characterization by fermentation of six different carbohydrates showed that the yeast isolates P2A have potential to ferment maltose, glucose and galactose. The strain P2A was evaluated further for their ethanol tolerance capacity. The strain can tolerate up to 12.5% concentration of ethanol. Pure strain of P2A was inoculated in anaerobic conditions with 200 rpm for 48 h at 30°C to be used for ethanol. The concentration of glucose after 72 h of fermentation for P2A was found to be 0.982 mg/mL.

In this review, we touch on the historical overview of natural products discovery from soil and discuss their classification up to date. New advancement on innovation and technological pipeline that contributed on the foundation of isolation of microbial biosynthetic diversity across soil environmental community have revealed massive reservoirs of as yet untapped natural product chemistry. We highlight the successful strategies that has emerged and threats that must be overcome to enable the development of a high throughput approach for natural product discovery from complex microbial communities.

ABSTRACT The continuous discharge of toxic materials into the environment has been an alarming issue faces around the globe. Hence, matching effort of monitoring activity is vital to coping with the overwhelming amount of metal ions. Along with the significant current research being conducted, this study aims to investigate the sensitivity of acetylcholinesterase (AChE) of Sabah porcupine fish, Diodon hystrix as an alternative biosensor in the detection of heavy metals. The enzyme was precipitated followed by the purification using ammonium sulfate precipitation and procainamide-affinity chromatography, respectively, with a total recovery of 66.67% with the specific activity of 2297.50 U/mg. The enzyme works optimally at pH 9 with the best incubation temperature of 30°C. The Michaelis constant (Km) and maximal velocity (Vmax) of 1.171 mM and 879257 mol/min/mg denotes the highest catalytic efficiency (Vmax/Km) of acetylthiocholine iodide (ATC) as its preferable substrate. Inhibition study tested on 10 metal ions resulted in increasing toxicity order of Cr6+ < Co2+ < Ag2+ < Cu2+ < Pb2+ < As5+ < Cd2+ < Zn2+ < Ni2+ < Hg2+, with only Hg2+ exhibited the half-maximal inhibitory concentration (IC50) of 0.48 mg/L. From the study, it suggests that the D. hystrix AChE as the potential conventional biosensor for heavy metals detection.