Roslinda Abd Malek

Anaerobic Probiotics: The Key Microbes for Human Health

Human gastrointestinal microbiota (HGIM) incorporate a large number of microbes from different species. Anaerobic bacteria are the dominant organisms in this microbial consortium and play a crucial role in human health. In addition to their functional role as the main source of many essential metabolites for human health, they are considered as biotherapeutic agents in the regulation of different human metabolites. They are also important in the prevention and in the treatment of different physical and mental diseases. Bifidobacteria are the dominant anaerobic bacteria in HGIM and are widely used in the development of probiotic products for infants, children and adults. To develop bifidobacteria-based bioproducts, therefore, it is necessary to develop a large-scale biomass production platform based on a good understanding of the ideal medium and bioprocessing parameters for their growth and viability. In addition, high cell viability should be maintained during downstream processing and storage of probiotic cell powder or the final formulated product. In this work we review the latest information about the biology, therapeutic activities, cultivation and industrial production of bifidobacteria.

Killer Yeast, a Novel Biological Control of Soilborne Diseases for Good Agriculture Practice

Aspergillus niger (A. niger) causes a disease called black mold on certain fruits and vegetables such as grapes, apricots, onions, and peanuts and is a common contaminant of food. Containment of this disease can reduce the amount of fruits, vegetables, and foods to be discarded, hence reducing the amounts of agricultural waste generated. Chemical control of A. niger has been partially successful, and fungicides are commonly used in the management of black mold. However, the risk of the establishment of resistant Aspergillus strains is considerable. Biocontrol, a nonhazardous alternative to the use of chemical fungicides, involves the use of biological processes to reduce crop loss and various microorganisms. Since it was first reported, the killer phenomenon in yeasts has been extensively studied in several genera and species, and its importance is gaining further recognition by industrialists. The food and beverage industries were among the first to explore the ability of toxin-producing yeasts to kill other fungus.

Medical and Cosmetic Applications of Fungal Nanotechnology: Production, Characterization, and Bioactivity

Nowadays, nanotechnology is widely applied for the development of highly efficient products in the pharmaceutical and cosmetic industries. Converting bioactive materials to nanoscale not only increases their biocompatibility but also increases their effectiveness, even when lower doses are used. Metal nanoparticles can be synthesized by fungal cells both intra- and extracellularly. Stabilization of the physical and chemical properties of various noble metal nanoparticles produced by fungi can be achieved through controlling the size, surface morphology, and surface chemistry of the nanoparticles. Intracellular synthesis provides smaller nanoparticles with well defined dimensions, but contributes to difficulty in downstream processing activity as compared with synthesis by extracellular methods. Recently, the production of nanoparticles from fungi has received extensive attention, owing to the capacity of fungi to produce nanoparticles extracellularly, a process that is more reliable and ecofriendly than intracellular methods, with relatively simple downstream processing. Fungi secrete extracellular enzymes for their survival and they control metal cation transportation to maintain intracellular homeostasis; when more protein is excreted nanoparticle synthesis is increased. To maximize nanoparticle synthesis, the rate of their synthesis can be increased through optimization of the total fungal cell mass and bioprocessing parameters, such as time of exposure, temperature, and pH. This will facilitate increased productivity in the fungal synthesis of nanoparticles for applications in the pharmaceutical and cosmetic industries.

Antioxidant Compounds of the Edible Mushroom Pleurotus ostreatus

Mushrooms have been used since centuries in many ancient cultures as source of food and medicine. However, until now the therapeutic values of mushrooms position this group of macrofungi as one of the major component in traditional medicine practice especially in South East Asia and China. Of different species of known mushrooms, Pleurotus spp. is widely known as part of food chain based on its high nutritional value. However, of the more than 70 species known, only few species are cultivated in mass production and used such as P. ostreatus, P. florida, and P. ajor-caju. However, P. ostreatus (widely known as oyster mushroom) received more attention in food industries based on its high growth rate and ease of cultivation using different substrates. This mushroom is rich of wide range of bioactive molecules of proven medicinal values with many therapeutic activities as anticancer, immunomodulatory, antiapoptotic, anti hypocholesterolemic, anti hyperglycemic, antimicrobial, anti-inflammatory, anti-osteoporetic, and many others. This work focuses on reviewing on the different classes of oyster mushroom bioactive compounds of antioxidant activities such as phenolics, beta carotene, lycopene, ascorbic acid, tocopherols, and ergosterols. This review provides also comprehensive information on the recent research to enhance the antioxidant properties through alteration of the cultivation strategy and addition of some compounds during the cultivation of P. ostreatus.

Mycoremediation: Decolourization Potential of Fungal Ligninolytic Enzymes

Textile industry is the most avid user for dyes. Rapidly growing interest in developing more synthetic commercial dyes from its native to endeavour human needs contributed to aesthetic problems to the environment and public health. Increasing concerns about colours in the effluents lead to worldwide efforts to develop more effective colour removal processes. However, the physical and chemical treatment methods of the discharge effluents are not economically feasible even if some of them are inefficient nowadays. Furthermore, liberating the hazardous product from secondary pollution from these methods acquires valid waste management system. Without proper discharge, azo dyes and associated chemicals may induce mutagenesis leading to toxicity in aquatic plants and animals. Utilization of mycoremediation of dyes as green chemistry technology has yet become a promising approach due to its clear picture of cost, eco-friendly and environmentally benign process as an alternative green solution to replace or supplement for current and future environmental issues. The bioremediation using fungi was reported to be more tolerant than bacteria and more efficient for decolorization as well as degradation of toxic chemicals. However, white-rot fungi are well known for their outstanding ability in bioremediation process. Their ability to produce highly non-specific extracellular enzymes allows them to degrade a wide array of pollutants resembling dyes and its derivatives. White-rot fungi secrete one or more of the three principle ligninolytic enzymes: lignin peroxidase (LiP, E.C. 1.11.1.14), Mn-dependent peroxidase (MnP, E.C. 1.11.1.13) and phenol oxidase (laccase) (Lac, E.C. 1.10.3.2) and other peroxidases. The present review discusses comprehensively the science and technology of biodegradation and fungal bioremediation of synthetic dyes.

The Edible Mushroom Pleurotus spp.: II. Medicinal Values

Mushrooms health benefit was recognized in the Orient from several thousand years ago as globally consumption and has third largest commercially production. The genus Pleurotus (oyster mushroom) is an organoleptic fast growing fungus which belongs to basidiomycota group. Although 70 species is discovered until now for this genus, but only few of them are available in market such as Pleurotus florida, P. sajor-caju and P. ostreatus. They have been used in human diet throughout the world due to their rich nutrients such as protein, fiber carbohydrate, minerals, vitamins and lipid. It should be noted that low amount calories, Sodium, fat and cholesterol is reported in this genus. Many pharmaceutical companies in the Far East and China are viewing the medicinal mushrooms as a rich source of innovative biomedical molecules. These molecules can be extracted from different part of oyster mushroom such as fruiting body, mycelia and culture broth. Mainly they are biopolymers including polysaccharides, proteins and nucleic acids as they are more variable to carry biological information. The medicinal properties of Pleurotus spp studied by several authors, as a result antitumor, immunomodulating, antiviral, antibacterial, antigenotoxic, antioxidant, anti-inflammatory, hypocholesterolamic, antihypertensive, antiinociceptive, anti-hyperglycaemic, anti-platelet-aggregating, antihepatoma, anti poliferative and antiatherosclerotic. In this chapter, biodivertsity of genus Pleurotus will be discussed regarding nutritional and bioactive compounds. Furthermore the prospective of oyster mushroom for therapeutic application and concept will be highlighted.

Effect of additives on Pleurotus ostreatus Growth on Agar medium

Oyster mushroom (Pleurotus ostreatus) is one of the most widely grown mushrooms worldwide. This type of fungus have been grown for centuries in green houses to produce mycelium and fruiting bodies and marketed as highly nutritious food. Like many other mushrooms, oyster mushroom characterized by lower growth rate which consume long time on agar medium for inoculum preparation for spawn preparation. Therefore, design of new cultivation medium to shorten the cultivation time on solid medium is necessary to reduce time and produce inoculum with less cost. This work was focused on optimization of agar medium (using the conventional potato dextrose agar medium PDA as base medium for growth and supplemented with other components such as malt extract, yeast extract, and sodium nitrates). The results clearly demonstrate that addition of malt extract and yeast extract support dense cell growth but not fast radial growth on agar medium. Addition of sodium nitrate in addition to malt and yeast extract, increase both of radial cell growth and dense growth as well. Therefore, for fast growth of Pleurotus ostreatus on agar medium its recommended to supplement the growth medium with malt extract, yeast extract, and sodium nitrate.

Effects of Different Carbon Sources for High Level Lactic Acid Production by Lactobacillus casei

The fermentation process utilization to produce lactic acid has been studied from carbohydrate source and another source because of several significant reasons. Above all the production of biotechnology construction is found to be less costly compared to chemical synthesis. The production of biodegradable lactic polymer from lactic acid utilization of raw material can easily be obtained from industrial wastes such as pineapple waste. The process can positively affect the environment by reducing the environmental problems. The aim of this study is to estimate the effects of glucose concentration of pineapple wastewater as the carbon source on the volume of Lactobacillus casei (L. casei) subspecies in producing lactic acid. Five different glucose concentrations as carbon source are used for production of high lactic acid in the fermentation process using L. casei. L.casei could be ingesting the glucose presented within the levels tested and converts all into lactic acid. The result shows efficient yields of 0.09 g lactic acid/g glucose. The highest level of lactic acid is at 125.71 g/l and was obtained from 100 % pineapple waste medium. When the carbon source is at 4 g/l, the level of lactic acid is decreased to 84.22 g/l. The fermentation time increases with the increment of sugars. It is more than double if the medium is composed of 100 % of pineapple waste. Therefore pineapple waste is the best alternative as carbon source for bacteria growth because it is more cost effective.