•Integration of ultrasound and liquid biphasic flotation for astaxanthin extraction.•Single-step cell disruptive extraction approach was carried out.•Optimization of various parameters for ...ultrasound-assisted liquid biphasic flotation.•Astaxanthin recovery of 83.73 ± 0.70% and partition coefficient of 157.83 ± 7.47.
The purpose of this investigation is to evaluate the implementation of ultrasound-assisted liquid biphasic flotation (LBF) system for the recovery of natural astaxanthin from Haematococcus pluvialis microalgae. Various operating conditions of ultrasound-assisted LBF systems such as the position of ultrasound horn, mode of ultrasonication (pulse and continuous), amplitude of ultrasonication, air flowrate, duration of air flotation, and mass of H. pluvialis microalgae were evaluated. The effect of ultrasonication on the cellular morphology of microalgae was also assessed using microscopic analysis. Under the optimized operating conditions of UALBF, the maximum recovery yield, extraction efficiency, and partition coefficient of astaxanthin were 95.08 ± 3.02%, 99.74 ± 0.05%, and 185.09 ± 4.78, respectively. In addition, the successful scale-up operation of ultrasound-assisted LBF system verified the practicability of this integrated approach for an effective extraction of natural astaxanthin.
•Utilization of food waste compost as an organic medium for microalgae cultivation.•Evaluation of microalgae growth and biochemical composition using organic medium.•Combination of up to 50% organic ...medium showed higher biomass yield.•Combination of up to 35% organic medium showed higher lipid and protein content.•Replacement of inorganic medium with organic medium is environmentally advantageous.
The present study investigates the prospective of substituting inorganic medium with organic food waste compost medium as a nutrient supplement for the cultivation of Chlorella vulgaris FSP-E. Various percentages of compost mixtures were replaced in the inorganic medium to compare the algal growth and biochemical composition. The use of 25% compost mixture combination was found to yield higher biomass concentration (11.1%) and better lipid (10.1%) and protein (2.0%) content compared with microalgae cultivation in fully inorganic medium. These results exhibited the potential of combining the inorganic medium with organic food waste compost medium as an effective way to reduce the cultivation cost of microalgae and to increase the biochemical content in the cultivated microalgae.
Acceleration of urbanization and industrialization has resulted in the drastic rise of waste generation with majority of them being biowaste. This constitutes a global challenge since conventional ...waste management methods (i.e., landfills) present environmental issues including greenhouse gases emissions, leachate formation and toxins release. A sustainable and effective approach to treat biowaste is through composting. Various aspects of composting such as compost quality, composting systems and compost pelletization are summarized in this paper. Common application of compost as fertilizer or soil amendment is presented with focus on the low adoption level of organic waste compost in reality. Rarely known, compost which is easily combustible can be utilized to generate electricity. With the analysis on critical approaches, this review aims to provide a comprehensive study on energy content of compost pellets, which has never been reviewed before. Environmental impacts and future prospects are also highlighted to provide further insights on application of this technology to close the loop of circular bioeconomy.
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•Conversion of waste to compost can reduce environmental pollution of organic waste.•Composting process, compost quality and composting systems are critically reviewed.•Compost can be utilized as fertilizer and energy fuel, promoting circular economy.•Production and combustion of compost fuel have high efficiency of energy recovery.•Optimizing composting process and composter can mitigate the environmental impacts.
This paper reviews composting process and utilization of compost for fertilizer and bioenergy to reduce waste volume, mitigate pollution and promote circular bioeconomy.
In the context of climate change and the increase of the energy demand, there is a need for carbon sequestration methods and sustainable fuels. This can be done by cultivation of microalgae, an ...unicellular microscopic algae that converts carbon dioxide into high-value bioproducts and energy. Moreover, microalgae can be used to assess the health of ecosystems such as lakes. Here we review microalgae for biofuel, for wastewater treatment and as bioindicators. We discuss the impact of processes based on microalgae using life cycle assessment. We present co-cultivation of microalgae with other microbes, and we compare conventional processes with processes integrating auto-flocculation, in situ transesterification and excretion.
•Four pre-treatment methods were studied for C-PC extraction from microalgae.•Higher PF and protein recovery were enhanced using sonication as pre-treatment.•Optimum power, duty cycle and sonication ...time were identified for C-PC production.
In this present study, microalgal phycobiliproteins were isolated and purified via potential biphasic processing technique for pharmaceutical as well as food applications. The algal pre-treatment techniques were studied to enhance the yield of microalgal phycobiliproteins from the biomass. The proposed methods were optimised to obtain the best recovery yield of phycobiliproteins that can be isolated from the biomass. The phycobiliproteins were further purified using liquid biphasic system. The results showed that microalgal phycobiliproteins of high purity and yield was achieved using sonication treatment (20% power, 50% duty cycle and 7 min of irradiation time) with the biphasic system, where the purification fold of 6.17 and recovery yield of 94.89% was achieved. This work will provide insights towards the effective downstream processing of biomolecules from microalgae.
The increased global demand for plastic materials has led to severe plastic waste pollution, particularly to the marine environment. This critical issue affects both sea life and human beings since ...microplastics can enter the food chain and cause several health impacts. Plastic recycling, chemical treatments, incineration and landfill are apparently not the optimum solutions for reducing plastic pollution. Hence, this review presents two newly identified environmentally friendly approaches, plastic biodegradation and bioplastic production using algae, to solve the increased global plastic waste. Algae, particularly microalgae, can degrade the plastic materials through the toxins systems or enzymes synthesized by microalgae itself while using the plastic polymers as carbon sources. Utilizing algae for plastic biodegradation has been critically reviewed in this paper to demonstrate the mechanism and how microplastics affect the algae. On the other hand, algae-derived bioplastics have identical properties and characteristics as petroleum-based plastics, while remarkably being biodegradable in nature. This review provides new insights into different methods of producing algae-based bioplastics (e.g., blending with other materials and genetic engineering), followed by the discussion on the challenges and further research direction to increase their commercial feasibility.
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•Marine plastic pollution endangers and affects aquatic wildlife and their habitat.•Interaction between algal enzymes and plastic polymers triggers biodegradation.•Bioplastics can be made using protein- and carbohydrate-based polymers from algae.•Production of polymers from algae can be enhanced through genetic engineering.•Conventional plastics could be fully replaced by algal bioplastics in the future.
In the recent years, microalgae have captured researchers’ attention as the alternative feedstock for various bioenergy production such as biodiesel, biohydrogen, and bioethanol. Cultivating ...microalgae in wastewaters to simultaneously bioremediate the nutrient-rich wastewater and maintain a high biomass yield is a more economical and environmentally friendly approach. The incorporation of algal–bacterial interaction reveals the mutual relationship of microorganisms where algae are primary producers of organic compounds from CO
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, and heterotrophic bacteria are secondary consumers decomposing the organic compounds produced from algae. This review would provide an insight on the challenges and future development of algal–bacterial consortium and its contribution in promoting a sustainable route to greener industry. It is believed that microalgal-bacterial consortia will be implemented in the near-future for sub-sequential treatment of wastewater bioremediation, bioenergy production and CO
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fixation, promoting sustainability and making extraordinary advancement in life sciences sectors.
Three-phase partitioning (TPP) is rapidly developing as a novel bioseparation technique for the separation and purification of biomolecules. TPP has been applied in a wide range of applications ...including enzyme stability and enhancement of its catalytic activity. The partitioning into three phases is mainly dependent on the concentration of alcohol and salt used. TPP provides high enzyme recovery and can be utilized along with external techniques such as ultrasound, microwave assisted, microaffinity ligand-facilitated and also ionic-liquid based. This technique has attracted interest in the large scale recovery of proteins from crude feedstocks or fermentation broths. In this review, the basic principles, refolding of proteins using TPP, key design variables of TPP, types of TPP, applications of TPP in food industry as well as the challenge of TPP were analyzed. The work presented in this review will be beneficial for further researches in TPP or related separation techniques.
Celotno besedilo
Dostopno za:
BFBNIB, DOBA, GIS, IJS, IZUM, KILJ, KISLJ, NUK, PILJ, PNG, SAZU, UILJ, UKNU, UL, UM, UPUK
•Non-catalytic transesterification with microwave processing for biofuel production.•Optimization studies done using response surface methodology, Box-Behnken design.•Biodiesel conversion yield of ...86% was obtained at the optimal condition.•Biodiesel that satisfies the EN14214 biodiesel standard was successfully produced.
The main transesterification used in industries involves the reaction with basic catalysts that caused unwanted soap formation, and time-consuming as post-treatment is needed. This creates the need for the utilization of a non-catalytic transesterification reaction under subcritical condition for the transformation of palm oil into biodiesel. This study evaluates the potential of using microwave technology to implement the non-catalytic transesterification for the efficient production of biodiesel. Response surface methodology (RSM) was implemented to maximise the non-catalytic biodiesel yield based on three variables: Dimethyl carbonate (DMC) to oil molar ratio, reaction temperature and reaction time. A maximum biodiesel yield of 86% was obtained with DMC to oil molar ratio of 9.5:1 at 167 °C after 2.5 hr of reaction. Also, its activation energy and pre-exponential factor were 44.88 kJ/mol and 7.88 × 103 min−1, respectively. Biodiesel quality that satisfies the EN14214 biodiesel standard was successfully produced under subcritical condition in the absence of catalysts via this microwave processing technology. This new processing method will enhance the biodiesel production and feasibility in terms of simplicity and less production step. Besides, it needs lower power consumption compared to non-catalytic supercritical method, which brings slight enhancement in cost reduction.
Lignocellulosic biomass has been recognized as promising feedstock for biofuels production. However, the high cost of pretreatment is one of the major challenges hindering large-scale production of ...biofuels from these abundant, indigenously-available, and economic feedstock. In addition to high capital and operation cost, high water consumption is also regarded as a challenge unfavorably affecting the pretreatment performance. In the present review, advances in lignocellulose pretreatment technologies for biofuels production are reviewed and critically discussed. Moreover, the challenges faced and future research needs are addressed especially in optimization of operating parameters and assessment of total cost of biofuel production from lignocellulose biomass at large scale by using different pretreatment methods. Such information would pave the way for industrial-scale lignocellulosic biofuels production. Overall, it is important to ensure that throughout lignocellulosic bioethanol production processes, favorable features such as maximal energy saving, waste recycling, wastewater recycling, recovery of materials, and biorefinery approach are considered.
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