scholarly journals Biotechnological production of xylitol from agricultural waste//Producción biotecnológica de xilitol a partir de residuos agrícolas

Biotecnia ◽  
2019 ◽  
Vol 22 (1) ◽  
pp. 126-134
Author(s):  
José Luis Espinoza-Acosta

Agricultural residues valorization has been an important issue over the last decades. Agricultural crop waste is an abundant, non-food, renewable, and low-cost feedstock to obtain attractive products for the food industry. The interest in replacing food ingredients such as artificial sweeteners with these obtained by biotechnological processes has grown in recent years, due to consumer’s high demand for low-calories foods and beverages without sacrificing taste. Several types of low caloric sweeteners are being obtained from the biotransformation of agricultural residues, with xylitol above all, for environmental, economic, and nutritional reasons. In recent years, the conversion of hydrolyzed agricultural residues into xylitol using enzymes, yeasts, and fungi has shown significant advances, although there are still many problems to be solved. This review presents the main advances in the use of microorganisms, substrates, and process conditions for the biotransformation of agricultural residues to xylitol. Besides, the main advantages and disadvantages of xylitol obtained by biotechnological routes compared to traditional chemical routes are discussed.RESUMENLa valorización de residuos agrícolas ha sido un tema importante en las últimas décadas. Los desechos de cultivos agrícolas son una materia prima abundante, no alimenticia, renovable y de bajo costo útil para obtener productos atractivos para la industria alimenticia. El interés por reemplazar ingredientes alimenticios de origen sintético por aquellos obtenidos por procesos biotecnológicos ha crecido en los últimos años debido a la gran demanda de los consumidores por los alimentos y bebidas con bajo contenido calórico sin sacrificar el sabor. Varios tipos de edulcorantes de bajo contenido calórico se han obteniendo a partir de la biotransformación de residuos agrícolas, destacando de todos ellos el xilitol por razones ecológicas, económicas y nutricionales. En los últimos años, la conversión de hidrolizados de residuos agrícolas en xilitol utilizando enzimas, levaduras y hongos ha mostrado avances importantes, aunque aún existen muchos problemas por resolver. En esta revisión se presentan los principales avances en el uso de microorganismos, sustratos y condiciones de proceso para la biotransformación de residuos agrícolas en xilitol. Además, se discuten las principales ventajas y desventajas del xilitol obtenido por rutas biotecnológicas comparado con las rutas químicas tradicionales.

2019 ◽  
Vol 9 (19) ◽  
pp. 3980 ◽  
Author(s):  
Saowanee Wijitkosum ◽  
Preamsuda Jiwnok

For an agricultural country such as Thailand, converting agricultural waste into biochar offers a potential solution to manage massive quantities of crop residues following harvest. This research studied the structure and chemical composition of biochar obtained from cassava rhizomes, cassava stems and corncobs, produced using a patented locally-manufactured biochar kiln using low-cost appropriate technology designed to be fabricated locally by farmers. The research found that cassava stems yielded the highest number of Brunauer-Emmett-Teller (BET) surface area in the biochar product, while chemical analysis indicated that corncobs yielded the highest amount of C (81.35%). The amount of H in the corncob biochar was also the highest (2.42%). The study also showed biochar produced by slow pyrolysis was of a high quality, with stable C and low H/C ratio. Biochar’s high BET surface area and total pore volume makes it suitable for soil amendment, contributing to reduced soil density, higher soil moisture and aeration and reduced leaching of plant nutrients from the rhizosphere. Biochar also provides a conducive habitat for beneficial soil microorganisms. The findings indicate that soil incorporation of biochar produced from agricultural crop residues can enhance food security and mitigate the contribution of the agricultural sector to climate change impacts.


2021 ◽  
Vol 105 (6) ◽  
pp. 2225-2242
Author(s):  
Cedric Schirmer ◽  
Rüdiger W. Maschke ◽  
Ralf Pörtner ◽  
Dieter Eibl

AbstractNo matter the scale, stirred tank bioreactors are the most commonly used systems in biotechnological production processes. Single-use and reusable systems are supplied by several manufacturers. The type, size, and number of impellers used in these systems have a significant influence on the characteristics and designs of bioreactors. Depending on the desired application, classic shaft-driven systems, bearing-mounted drives, or stirring elements that levitate freely in the vessel may be employed. In systems with drive shafts, process hygiene requirements also affect the type of seal used. For sensitive processes with high hygienic requirements, magnetic-driven stirring systems, which have been the focus of much research in recent years, are recommended. This review provides the reader with an overview of the most common agitation and seal types implemented in stirred bioreactor systems, highlights their advantages and disadvantages, and explains their possible fields of application. Special attention is paid to the development of magnetically driven agitators, which are widely used in reusable systems and are also becoming more and more important in their single-use counterparts.Key Points• Basic design of the most frequently used bioreactor type: the stirred tank bioreactor• Differences in most common seal types in stirred systems and fields of application• Comprehensive overview of commercially available bioreactor seal types• Increased use of magnetically driven agitation systems in single-use bioreactors


2019 ◽  
Vol 8 (4) ◽  
pp. 1499-1502

The present work focuses the potentiality of agricultural waste, Tamarind bark for removal of arsenic from industry effluent. One parameter model was performed to evaluate time, dosage, concentration of arsenic ion and pH. The process conditions were determined as contact time 50 minutes, dosage 0.85gm, metal ion concentration 0.1g/l and pH was 4.The experimental values are analysed with adsorption isotherms to know the capacity of biosorbent. The data well explained Langmuir model compared to Freundlich model. The mechanism involved in biosorption was tested by using kinetic expressions of first and second order, but the given values are best suited to second order kinetics. The maximum removal of arsenic using low cost biosorbent of tamarind bark was found to be 68%.


2021 ◽  
Vol 8 ◽  
Author(s):  
Libin Yang ◽  
Daekwon Park ◽  
Zhao Qin

Mycelium-based bio-composite materials have been invented and widely applied to different areas, including construction, manufacturing, agriculture, and biomedical. As the vegetative part of a fungus, mycelium has the unique capability to utilize agricultural crop waste (e.g., sugarcane bagasse, rice husks, cotton stalks, straw, and stover) as substrates for the growth of its network, which integrates the wastes from pieces to continuous composites without energy input or generating extra waste. Their low-cost and environmentally friendly features attract interest in their research and commercialization. For example, mycelium-based foam and sandwich composites have been actively developed for construction structures. It can be used as synthetic planar materials (e.g., plastic films and sheets), larger low-density objects (e.g., synthetic foams and plastics), and semi-structural materials (e.g., paneling, flooring, furniture, decking). It is shown that the material function of these composites can be further tuned by controlling the species of fungus, the growing conditions, and the post-growth processing method to meet a specific mechanical requirement in applications (e.g., structural support, acoustic and thermal insulation). Moreover, mycelium can be used to produce chitin and chitosan, which have been applied to clinical trials for wound healing, showing the potential for biomedical applications. Given the strong potential and multiple advantages of such a material, we are interested in studying it in-depth and reviewing the current progress of its related study in this review paper.


Author(s):  
Gonzalo Flores-Morales ◽  
Mónica Díaz ◽  
Patricia Arancibia-Avila ◽  
Michelle Muñoz-Carrasco ◽  
Pamela Jara-Zapata ◽  
...  

Abstract A feasibility analysis of tertiary treatment for Organic Liquid Agricultural Waste is presented using filamentous algae belonging to the genus Cladophora sp. as an alternative to chemical tertiary treatment. The main advantages of tertiary treatments that use biological systems are the low cost investment and the minimal dependence on environmental variables. In this work we demonstrate that filamentous algae reduces the nutrient load of nitrate (circa 75%) and phosphate (circa 86%) from the organic waste effluents coming from dairy farms after nine days of culture, with the added advantage being that after the treatment period, algae removal can be achieved by simple procedures. Currently, the organic wastewater is discarded into fields and local streams. However, the algae can acquire value as a by-product since it has various uses as compost, cellulose, and biogas. A disadvantage of this system is that clean water must be used to achieve enough water transparency to allow algae growth. Even so, the nutrient reduction system of the organic effluents proposed is friendly to the ecosystem, compared to tertiary treatments that use chemicals to precipitate and collect nutrients such as nitrates and phosphates.


Crystals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 887
Author(s):  
Chunhua Feng ◽  
Buwen Cui ◽  
Haidong Ge ◽  
Yihong Huang ◽  
Wenyan Zhang ◽  
...  

Recycled aggregate is aggregate prepared from construction waste. With the development of a global economy and people’s attention to sustainable development, recycled aggregate has shown advantages in replacing natural aggregate in the production of concrete due to its environmental friendliness, low energy consumption, and low cost. Recycled aggregate exhibits high water absorption and a multi-interface transition zone, which limits its application scope. Researchers have used various methods to improve the properties of recycled aggregate, such as microbially induced calcium carbonate precipitation (MICP) technology. In this paper, the results of recent studies on the reinforcement of recycled aggregate by MICP technology are synthesized, and the factors affecting the strengthening effect of recycled aggregate are reviewed. Moreover, the strengthening mechanism, advantages and disadvantages of MICP technology are summarized. After the modified treatment, the aggregate performance is significantly improved. Regardless of whether the aggregate was used in mortar or concrete, the mechanical properties of the specimens were clearly improved. However, there are some issues regarding the application of MICP technology, such as the use of an expensive culture medium, a long modification cycle, and untargeted mineralization deposition. These difficulties need to be overcome in the future for the industrialization of regenerated aggregate materials via MICP technology.


Foods ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1626
Author(s):  
Regina Kratzer ◽  
Michael Murkovic

Microalgal products are an emerging class of food, feed, and nutraceuticals. They include dewatered or dried biomass, isolated pigments, and extracted fat. The oil, protein, and antioxidant-rich microalgal biomass is used as a feed and food supplement formulated as pastes, powders, tablets, capsules, or flakes designed for daily use. Pigments such as astaxanthin (red), lutein (yellow), chlorophyll (green), or phycocyanin (bright blue) are natural food dyes used as isolated pigments or pigment-rich biomass. Algal fat extracted from certain marine microalgae represents a vegetarian source of n-3-fatty acids (eicosapentaenoic acid (EPA), docosahexaenoic acid (DHA), γ-linolenic acid (GLA)). Gaining an overview of the production of microalgal products is a time-consuming task. Here, requirements and options of microalgae cultivation are summarized in a concise manner, including light and nutrient requirements, growth conditions, and cultivation systems. The rentability of microalgal products remains the major obstacle in industrial application. Key challenges are the high costs of commercial-scale cultivation, harvesting (and dewatering), and product quality assurance (toxin analysis). High-value food ingredients are commonly regarded as profitable despite significant capital expenditures and energy inputs. Improvements in capital and operational costs shall enable economic production of low-value food products going down to fishmeal replacement in the future economy.


2016 ◽  
Vol 723 ◽  
pp. 572-578
Author(s):  
Li Fu ◽  
Qi Chi Le ◽  
Xi Bo Wang ◽  
Xuan Liu ◽  
Wei Tao Jia

In recent years, the development and utilization of renewable generation have attracted more and more attention, and the grid puts forward higher requirements to the energy storage technology, especially for security, stability and reliability. The liquid metal battery (LMB) consists of two liquid metal electrodes and a molten salt electrolyte, which will be segregated into three liquid layers naturally. Being low-cost and long-life, it is regarded as the best choice for grid-level large-scale energy storage. This paper describes the main structure and working principle of the LMB, analyzes the advantages and disadvantages of the LMB when compared with the traditional batteries, and explores the feasibility and economy when it is used as a kind of large-scale energy storage applied in the power grid. The paper also makes a comprehensive comparison on the performance of several LMBs, and points out the LMB’s research and development in the future.


2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Avtar Singh ◽  
Amanjot Kaur ◽  
Anita Dua ◽  
Ritu Mahajan

Xylano-pectino-cellulolytic enzymes are valuable enzymes of the industrial sector. In our earlier study, we have reported a novel and cost effective methodology for the qualitative screening of cellulase-free xylano-pectinolytic microorganisms by replacing the commercial, highly expensive substrates with agricultural residues, but the microorganisms with xylanolytic, pectinolytic, cellulolytic, xylano-pectinolytic, xylano-cellulolytic, pectino-cellulolytic, and xylano-pectino-cellulolytic potential were obtained. The probability of getting the desired combination was low, so efforts were made to further improve this cost effective methodology for obtaining the high yield of the microbes capable of producing desired combination of enzymes. By inclusion of multiple enrichment steps in sequence, using only practically low cost substrates and without any nutrient media till primary screening stage, this improved novel protocol for screening gave only the desired microorganisms with xylano-pectino-cellulolytic activity. Using this rapid, efficient, cost effective, and improved methodology, microbes with required combination of enzymes can be obtained and the probability of getting the desired microorganisms is cent percent. This is the first report presenting the methodology for the isolation of xylano-pectino-cellulolytic positive microorganisms at low cost and consuming less time.


2014 ◽  
Vol 699 ◽  
pp. 221-226
Author(s):  
Nurul Hanim Razak ◽  
Md. Razali Ayob ◽  
M.A.M. Zainin ◽  
M.Z. Hilwa

Eggshells and rice husk, two types of notable agricultural waste were used as bioadsorbent to remove Methylene Blue dye (MBD) in aqueous solution. This study was to investigate the performance of these two bioadsorbents in removing MBD. The removal percentage, adsorption capacity, and porosity characterization were examined. The method applied was a physical filtration. UV-VIS Spectrophotometer was used to determine the efficiency of the bioadsorbents in MBD adsorption. The highest removal percentage at the most concentrated MBD were 51% and 98% for eggshells and rice husks respectively. Meanwhile the characterization of rice husks pore size and volume proves that higher adsorptivity towards dye compares to eggshells porosity. It was concluded that the eggshells and rice husks bioadsorbents was successful to treat industrial textile wastewater with rice husks as the most efficient bioadsorbent in removing MBD.


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