Optimization and characterization of exo-polygalacturonase by Aspergillus niger cultured via solid state fermentation

Polygalacturonases represent an important member of pectinases group of enzymes with immense industrial applications. The activity of exo-polygalacturonase produced by Aspergillus niger was studied in solid state fermentation (SSF) using Nephrolepis biserrata leaves as substrate. Central composite design (CCD) was used to optimize four significant variables resulted from the screening process that has been initially analyzed for the production of exo-polygalacturonase which are incubation time, temperature, concentration of pectin and moisture content. The optimum exo-polygalacturonase production obtained was 54.64 U/g at 120 hours of incubation time, temperature at 340C, 5.0 g/L of pectin concentration and 75.26% of moisture content. For partial characterization of exo-polygalacturonase, the optimum temperature and pH were obtained at 50°C and pH 4.0, respectively. SDS-PAGE analysis showed that molecular weight of exo-polygalacturonase were 35 and 71 kDa. This study has revealed a significant production of exo-polygalacturonase by A. niger under SSF using cheap and easily available substrate and thus could found immense potential application in industrial sectors and biotechnology

An overview of the cultivation and commercialization of the caterpillar fungus, Ophiocordyceps sinensis sited in the Tibetan Plateau and the Himalayan forests of Bhutan and Nepal

Ophiocordyceps sinensis is a unique entomopathogenic fungus and valuable Chinese medicine resource that has been employed for treating various human conditions. Limited O. sinensis in the wild due to over-exploitation has led it to the brink of extinction. This caused a massive disparity between supply and demand, resulting in skyrocketing prices. The dumping of counterfeit products in the market also caused the need for quality control. In this review, effort has been made to understand the development of O. sinensis and its life cycle, in which the possible cultivation method can be discussed. Additionally, it also summarizes the analytical method for quality control measures in order to ensure the quality of artificially cultivated O. sinensis are on par or even better than the wild. Furthermore, the commercialization of artificially cultivated Cordyceps is lightly touched. Despite these challenges, research into the cultivation of Ophiocordyceps sinensis continues, as it has the potential to provide a sustainable source of the fungus for medicinal purposes. Some pharmaceutical companies have already developed products containing Ophiocordyceps sinensis, and further research may lead to the discovery of new therapeutic applications for the fungus. However, it is important to ensure that the cultivation and commercialization of Ophiocordyceps sinensis is done in an ethical and sustainable manner, to avoid further depletion of the wild populations of the fungus

Hollow Fiber Membrane as a Carrier for Enzyme Immobilization

Cyclodextrin (CD) is produced from starch by an enzymatic conversion catalyzed by cyclodextrin glucanotransferase (CGTase). CD has been used in a wide range of industries, especially in food, cosmetic, pharmaceutical, and agrochemical industries, due to its ability to improve the physicochemical properties of organic molecules, conferring greater chemical resistance to environmental factors, higher solubility, and reduced volatility (Ching et al. 2022). The commercialization of CGTase for industrial purposes is highly challenging due to the instability of the CGTase, sensitivity to the process condition, and high cost of isolation and purification (Guzik, Hupert-Kocurek, and Wojcieszyńska 2014; Mohamad et al. 2015). The instability of CGTase during the reaction process results in low yield CD. Therefore, enzyme immobilization has been applied to improve CGTase stability and achieve higher CD yields

Improved heterocyclic aromatic hydrocarbon compound adsorption using functionalised rice husk biochar

Carbazole (CBZ) is a hazardous heterocyclic aromatic hydrocarbon (HAH) that pollutes water bodies, and the treatment remains a challenge due to its high persistence in the environment. This study chemically modified rice husk biochar (RHB) with starch derivative (DS) to develop an effective adsorbent. Thus, functionalised RHB with starch derivative (RHBDS) was synthesised to remove CBZ from synthetic wastewater. Based on a Box-Behnken design, the DS functionalisation optimisation was successfully performed. The parameters, including RHB mass of (5–10) g, DS concentration of (1–5)% w/v, and sonication period of (1–5) min, were analysed using Design Expert. These parameters were then utilised to investigate the optimal conditions (removal rate response and adsorption capacity) for the adsorbent. The removal rate and the adsorption capacity ranged from 83.85 to 98.94 % and 335.41 to 395.76 mg/g, respectively. Consequently, the RHB mass of 6.50 g, DS concentration of 1 % w/v, and sonication period of 5 min within the experimental domain exhibited the best conditions with desirability of 1.0. The 92.67 % removal rate and adsorption capacity of 370.59 mg/g were also obtained under optimal conditions. Compared to RHB, RHBDS demonstrated four times the adsorption capacity for the CBZ removal from synthetic water, which were 23.03 mg/g and 98.01 mg/g, respectively. Therefore, the RHBDS compound could be a promising adsorbent in removing CBZ from wastewater

Bioconversion of starch to maltooligosaccharides (MOS) by the reaction of maltogenic amylase

Maltogenic amylase is one of the significant enzymes in oligosaccharides synthesis. Its ability to utilise multiple substrates and catalyse hydrolysis and transglycosylation reactions simultaneously makes it a unique biocatalyst. The catalysis could be exploited in many ways to obtain oligosaccharides of different lengths and various modified sugars. Nonetheless, one of the major drawbacks of substrate hydrolysis to produce oligosaccharides is the low production of MOS with higher degree of polymerisation. To address this issue, reaction parameter optimisation was performed via one-factor-at-a-time (OFAT) approach on the production of MOS from soluble starch hydrolysis using maltogenic amylase from Bacillus lehensis G1 (MAG1). Optimisation of MAG1 loading, soluble starch loading, temperature, time and pH resulted in the production of 84.87 mg/g MOS with polymerisation degree of 3 to 7 compared to that of 51.60 mg/g obtained before the optimisation process, which recorded 1.64-fold increment. Among all parameters, soluble starch loading gave the most significant impact on the MOS production as the reaction equilibrium is highly affected by substrate concentration. The occurrence of MOS with polymerisation degree of 4 and above, which resulted from starch hydrolysis further confirms the endo-type of MAG1. Because starch is an abundant and inexpensive source of carbohydrate in the world, this study provides a cost-effective MOS production process which is highly relevant for industry

Lignins as natural active ingredients for Cosmetics: A Review

Renewable, natural and biocompatible characteristic of lignin portray a huge milestone in cosmeceutical applications. The wide availability of lignin which exist in abundance in nature and from low-cost biowaste has put this polymer as one of the highly promising elements to be explored for replacing the common chemical-based ingredients in cosmetics. This review briefly summarises the detection methods of lignin and several common extraction and isolation methods of lignin. Several potential applications of lignin in cosmetic products which include ultraviolet protection, anti-ageing, antimicrobial properties, and others are also discussed. The advancement in technology and the increased awareness in health and wellness has speed up the research among the experts in finding the most appropriate natural substances to be able to replace the harmful and toxic ingredients in cosmeceutical products. The positive findings obtained from various studies shown in this review has lighten the future of this complex heterogeneous macromolecule for a more sustainable lifestyle of human being

Extraction and characterization of keratin from chicken and swiftlet feather

Keratin is a durable and fibrous protein of hair, nails, horns, hoofs, feathers and the epithelial cells in the outermost layers of the skin. Keratin in animals mainly presents in vertebrates such as mammals, birds and reptiles including chicken and swiftlet. This study aims to characterize keratin extracted from chicken and swiftlet feathers. The extraction of the keratin performed using dimethyl sufoxide (DMSO) at high temperature. The extracted keratin from both samples were used for the characterization process using Bradford protein assay, CHNS analysis and Fourier-transform infrared (FTIR) spectroscopy. This study showed that keratin extract of swiftlet feather showed higher protein concentration (0.813 mg/mL) than keratin extract of chicken feather (0.646 mg/ml). The highest composition for keratin extract is hydrogen which are 4.97% for keratin extract from swiftlet feathers and 3.12% for keratin extract from chicken feathers. FTIR analysis exhibited that carboxyl groups and amino groups are presence in both keratin samples however, the protein value is higher in swiftlet feathers compared to chicken feathers. This study's outcome is significant in discovering keratin extract from swiftlet feathers containing high protein content due to the breakdown of disulfide bonds. Furthermore, this research is the first report on keratin characterization from swiftlet feathers that would be useful for high value future keratin study

Adequacy of contract provision in managing construction failure

In managing construction failure, normally efforts are made to identify the possible cause of failure and seek for the possible solution of the problems faced. Currently, there is no clear guideline available either within existing contract documents or legislations that can be used as a guide to resolve construction failure cases. Hence, this study has been undertaken to identify the limitations of current contract provisions which related to construction failure. It is conducted to evaluate the adequacy of contractual provisions in contract documents. The methodology adopted for this study includes literature research, interviews and questionnaire surveys with selected professionals in construction industry and legal sector. The findings of the study show that the limitations in current contractual provisions are eminent. It is also found that there is a need for consideration of inclusion of new provisions to be implemented into contract document. Despite there may be a difference of ideas between the respondents from construction industry and legal sector regarding to limitations of law and contract to solve construction failure cases. This study also made some proposal of important items that should be considered for improving current contract provisions

Development of organic porous material from pineapple waste as a support for enzyme and dye adsorption

The transformation of agricultural wastes such as pineapple waste into valuable product such as biochar will be of great advantage. Biochar is a black carbon produced by pyrolysis which can act as good adsorbent for organic substances due to the high porosity characteristic. Due to the instability and the non-recyclability factor of free enzymes, the use of immobilized enzyme is getting more attraction. Furthermore, biochar or activated carbon (AC) has been widely used in industries to adsorb pollution such as dye. In this study, process pyrolysis was used to convert pineapple waste biomass (PWB) into useful adsorbent such as biochar (BC) and activated carbon (AC) for lipase immobilization and RBBR dye adsorption. Several steps such as impregnation of PWbB with nitric acid, and process pyrolysis of pineapple waste at various temperatures and residence time have been performed. Studies of characterization of biochar such as Thermogravimetric analysis (TGA), Brunauer – Emmett – Teller (BET), Fourier Transform Infra-Red (FTIR) and Scanning Electron Microscopy (SEM) were accomplished to analyze the differences in performance. The performance of BC in lipase immobilization and RBBR dye adsorption were investigated by varying parameters i.e. initial concentration, physical size of PWB (grounded and non-grounded pineapple waste (PW) biomas) and physical size of BC (crushed and non-crushed BC). The achievements of generated BC were compared with commercial AC. The result shows the highest amount of protein adsorbed during immobilization was achieved at F500 1 h PWbB (92.99%). Meanwhile, the maximum dye removal was achieved at F 600.5 h PWbB (83.59%). Adsorption kinetics studies insinuate that the overall process follows the pseudo-first-order where the process was influenced by intraparticle and film diffusion while equilibrium isotherm studies is best described by Langmuir isotherm models. As a conclusion, the conventional liability burden of pineapple waste is possible to be transformed into valuable commodity especially for waste treatment

Enzymatic hydrolysis of pretreated kenaf using a recombinant xylanase: effects of reaction conditions for optimum hemicellulose hydrolysis

An efficient hemicellulose hydrolysis has now become a crucial step for xylooligosaccharides production for food additives and nutraceuticals industries. In this study, xylanase hydrolysis of pretreated hemicellulosic kenaf (Hibiscus cannabinus) for substantial hemicellulose hydrolysis was demonstrated. Experiments were performed primarily to investigate the effect of several critical reaction conditions towards the enzymatic hydrolysis of the pre-treated kenaf. The effects of various ranges of reaction conditions (substrate loading, xylanase loading, pH, temperature and time) were systematically and thoroughly studied. The study of hemicellulosic kenaf conversion using single enzyme was proven to effectively yield up to 59% of conversion after 48 h incubation using 3% (w/v) of substrate loading and 400 U of xylanase loading at 50°C in pH 4.0 buffer systems. The use of a single xylanase on the pre-treated kenaf was a key parameter in understanding the action of the main hemicellulose degrading enzyme towards hydrolysing the hemicellulose backbone of the pre-treated kenaf. Enzyme feeding strategy was also conducted and the results revealed that a batch feeding strategy of 400 U xylanase loading yielded the highest hemicellulose hydrolysis compared to the other fed batch enzyme feeding strategy. It was concluded that each reaction conditions and enzyme feeding strategy gave a significant impact towards the enzymatic hydrolysis and the use of optimum reaction conditions resulted in a high product yield at the end of the reaction. With the discovery of the importance of each reaction conditions involved in a hydrolysis, this study highlights the need for a comprehensive investigation on the reaction conditions using a mixture of enzymes towards achieving a complete hydrolysis with a higher product yield