Astaxanthin is a high value keto‐carotenoid pigment renowned for its commercial application in various industries comprising aquaculture, food, cosmetic, nutraceutical and pharmaceutical. Among the ...verified bio‐resources of astaxanthin are red yeast Phaffia rhodozyma and green alga Haematococcus pluvialis. The supreme antioxidant property of astaxanthin reveals its tremendous potential to offer manifold health benefits among aquatic animals which is a key driving factor triggering the upsurge in global demand for the pigment. Numerous scientific researches devoted over a number of years have persistently demonstrated the instrumental role of astaxanthin in targeting several animal health conditions. This review article evaluates the current best available evidence to judge the beneficial usage of astaxanthin in aquaculture industry. Most apparent is the profound effect on pigmentation, where astaxanthin is frequently utilized as an additive in formulated diets to boost and improve the coloration of many aquatic animal species, and subsequently product quality and price. Moreover, the wide range of other physiological benefits that this biological pigment confers to these animals is also presented which include various improvements in survival, growth performance, reproductive capacity, stress tolerance, disease resistance and immune‐related gene expression.
Microalgae have a diverse application in food, pharmaceutical, beauty, animal feed and bioenergy industry. The demand for high‐quality pure microalgae biomass has steered the large‐scale production ...of microalgae in the photobioreactor. The usage of light‐emitting diodes (LEDs) as a light source is gaining attention as to conventional fluorescent lamps due to the higher energy conversion ratio, lower heat dissipation and its flexible application in photobioreactors. Besides, the narrow spectrum of LEDs could efficiently promote specific compounds in microalgae. This article reviews the influence of using various LED spectra on the biomass and lipid composition of microalgae. In addition, suggestions on the use of different LEDs cultivating common microalgae species in aquaculture are provided.
•Current trends on analytical technique for EDCs analysis are reviewed.•Sample storage and preservation to ensure integrity of result are discussed.•Advantages and limitations of each technique are ...analyzed using SWOT analysis.•Analytical strategies and future trends for EDCs is reviewed and presented.
Endocrine disrupting compounds (EDCs) have been widely reported as potential carcinogenic threats to the human population. The release of EDCs to environmental compartments, such as water, sediment, and biota, has been monitored extensively. Considering the typically low levels of EDC concentrations found in environmental samples and the complexity of biota matrices, the main challenge is with the extraction and cleanup of samples, as well as with finding a sensitive enough instrumentation system for analyte detection. This paper presents a review of recent trends in the analysis of EDCs in environmental matrices. The focus of this review is three classes of environmentally important EDCs; namely, pharmaceuticals, estrogenic hormones, and alkylphenol compounds. Discussions about state-of-the-art instrumentation and sample preparation techniques, as well as a review of sample storage and preservation, are highlighted. Overall, the use of LC-MS-MS as an instrumentation technique has increased over the past 15 years.
The world energy crisis and increased greenhouse gas emissions have driven the search for alternative and environmentally friendly renewable energy sources. According to life cycle analysis, ...microalgae biofuel is identified as one of the major renewable energy sources for sustainable development, with potential to replace the fossil-based fuels. Microalgae biofuel was devoid of the major drawbacks associated with oil crops and lignocelluloses-based biofuels. Algae-based biofuels are technically and economically viable and cost competitive, require no additional lands, require minimal water use, and mitigate atmospheric CO2. However, commercial production of microalgae biodiesel is still not feasible due to the low biomass concentration and costly downstream processes. The viability of microalgae biodiesel production can be achieved by designing advanced photobioreactors, developing low cost technologies for biomass harvesting, drying, and oil extraction. Commercial production can also be accomplished by improving the genetic engineering strategies to control environmental stress conditions and by engineering metabolic pathways for high lipid production. In addition, new emerging technologies such as algal-bacterial interactions for enhancement of microalgae growth and lipid production are also explored. This review focuses mainly on the problems encountered in the commercial production of microalgae biofuels and the possible techniques to overcome these difficulties.
Display omitted
•NH3 recovery from thermophilic composting of organic sludge to culture microalgae.•Calcium hydroxide dosing accelerated ammonia volatilization.•Geobacillus as the dominant bacteria ...for enhancing NH3 recovery.
A modified outdoor large-scale nutrient recycling system was developed to compost organic sludge and aimed to recover clean nitrogen for the cultivation of high-value-added microalgae. This study investigated the effect of calcium hydroxide addition on enhancing NH3 recovery in a pilot-scale reactor self-heated by metabolic heat of microorganisms during thermophilic composting of dewatered cow dung. 350 kg-ww of compost was prepared at the ratio of 5: 14: 1 (dewatered cowdung: rice husk: compost-seed) in a 4 m3 cylindrical rotary drum composting reactor for 14 days of aerated composting. High compost temperature up to 67 °C was observed from day 1 of composting, proving that thermophilic composting was achieved through the self-heating process. The temperature of compost increases as microbial activity increases and temperature decreases as organic matter decreases. The high CO2 evolution rate on day 0–2 (0.02–0.08 mol/min) indicated that microorganisms are most active in degrading organic matter. The increasing conversion of carbon demonstrated that organic carbon was degraded by microbial activity and emitted as CO2. The nitrogen mass balance revealed that adding calcium hydroxide to the compost and increasing the aeration rate on day 3 volatilized 9.83 % of the remaining ammonium ions in the compost, thereby improving the ammonia recovery. Moreover, Geobacillus was found to be the most dominant bacteria under elevated temperature that functions in the hydrolysis of non-dissolved nitrogen for better NH3 recovery. The presented results show that by thermophilic composting 1 ton-ds of dewatered cowdung for NH3 recovery, up to 11.54 kg-ds of microalgae can be produced.
Display omitted
•Successful thermophilic composting of shrimp sludge through self-heating.•Clean nitrogen (ammonia) recovered used for high-value microalgae cultivation.•Shrimp sludge compost ...application as soil conditioner for enhanced mango growth.
Due to the rapid growth of the aquaculture industry, large amounts of organic waste are released into nature and polluted the environment. Traditional organic waste treatment such as composting is a time-consuming process that retains the ammonia (NH3) in the compost, and the compost produced has little economic value as organic fertilizer. Illegal direct discharge into the environment is therefore widespread. This study investigates the recovery of NH3 through thermophilic composting of shrimp aquaculture sludge (SAS) and its application as a soil conditioner for the growth of mango plants. A maximum composting temperature of 57.10 °C was achieved through self-heating in a 200 L bench-scale reactor, resulting in NH3 recovery of 224.04 mol/ton-ds after 14 days. The addition of calcium hydroxide and increased aeration have been shown to increase NH3 volatilization. The recovered NH3 up to 3 kg-N can be used as a source of clean nitrogen for high-value microalgae cultivation, with a theoretical yield of up to 34.85 kg-algae of microalgae biomass from 1 ton-ds of SAS composting. Despite the high salinity, SAS compost improved mango plant growth and disease resistance. These results highlight the potential of SAS compost as a sustainable source of clean nitrogen for microalgae cultivation and soil conditioner, contributing to a waste-free circular economy through nutrient recycling and sustainable agriculture.
Fucoxanthin is a major carotenoid in brown macroalgae and diatoms that possesses a broad spectrum of health benefits. This review evaluated the research trends of the fucoxanthin field from 1928 to ...June 2021 using the bibliometric method. The present findings unraveled that the fucoxanthin field has grown quickly in recent years with a total of 2080 publications. Japan was the most active country in producing fucoxanthin publications. Three Japan institutes were listed in the top ten productive institutions, with Hokkaido University being the most prominent institutional contributor in publishing fucoxanthin articles. The most relevant subject area on fucoxanthin was the agricultural and biological sciences category, while most fucoxanthin articles were published in
. A total of four research concepts emerged based on the bibliometric keywords analysis: "bioactivities", "photosynthesis", "optimization of process'', and "environment". The "bioactivities" of fucoxanthin was identified as the priority in future research. The current analysis highlighted the importance of collaboration and suggested that global collaboration could be the key to valorizing and efficiently boosting the consumer acceptability of fucoxanthin. The present bibliometric analysis offers valuable insights into the research trends of fucoxanthin to construct a better future development of this treasurable carotenoid.
► Anaerobic digestion (AD) of food waste (FD) was conducted at high OLR for 225days. ► High CH4 yield and high VS reduction were achieved at high OLR simultaneously. ► The cell density in the sludge ...increased to 15 times that in the original seed sludge. ► The cell density increased during the periods when there was no organic loading. ► The maximum OLR was estimated around 10.5kg-VSm−3day−1 in a single-stage wet AD of FD.
Anaerobic digestion of food waste was conducted at high OLR from 3.7 to 12.9kg-VSm−3day−1 for 225days. Periods without organic loading were arranged between the each loading period. Stable operation at an OLR of 9.2kg-VS (15.0kg-COD) m−3day−1 was achieved with a high VS reduction (91.8%) and high methane yield (455mLg-VS-1). The cell density increased in the periods without organic loading, and reached to 10.9×1010cellsmL−1 on day 187, which was around 15 times higher than that of the seed sludge. There was a significant correlation between OLR and saturated TSS in the sludge (y=17.3e0.1679×, r2=0.996, P<0.05). A theoretical maximum OLR of 10.5kg-VS (17.0kg-COD) m−3day−1 was obtained for mesophilic single-stage wet anaerobic digestion that is able to maintain a stable operation with high methane yield and VS reduction.
The usage of cladocerans as non-model organisms in ecotoxicological and risk assessment studies has intensified in recent years due to their ecological importance in aquatic ecosystems. The molecular ...assessment such as gene expression analysis has been introduced in ecotoxicological and risk assessment to link the expression of specific genes to a biological process in the cladocerans. The validity and accuracy of gene expression analysis depends on the quantity, quality and integrity of extracted ribonucleic acid (RNA) of the sample. However, the standard methods of RNA extraction from the cladocerans are still lacking. This study evaluates the extraction of RNA from tropical freshwater cladocerans Moina micrura using two methods: the phenol-chloroform extraction method (QIAzol) and a column-based kit (Qiagen Micro Kit). Glycogen was introduced in both approaches to enhance the recovery of extracted RNA and the extracted RNA was characterised using spectrophotometric analysis (NanoDrop), capillary electrophoresis (Bioanalyzer). Then, the extracted RNA was analysed with reverse transcription polymerase chain reaction (RT-PCR) to validate the RNA extraction method towards downstream gene expression analysis. The results indicate that the column-based kit is most suitable for the extraction of RNA from M. micrura, with the quantity (RNA concentration = 26.90 ± 6.89 ng/μl), quality (A260:230 = 1.95 ± 0.15, A280:230 = 1.85 ± 0.09) and integrity (RNA integrity number, RIN = 7.20 ± 0.16). The RT-PCR analysis shows that the method successfully amplified both alpha tubulin and actin gene at 33-35 cycles (i.e. Ct = 32.64 to 33.48). The results demonstrate that the addition of glycogen is only suitable for the phenol-chloroform extraction method. RNA extraction with high and comprehensive quality control assessment will increase the accuracy and reliability of downstream gene expression, thus providing more ecotoxicological data at the molecular biological level on other freshwater zooplankton species.
•Edible jellyfishes are rich in protein and minerals while low in fats and calories.•Major amino acids present in edible jellyfishes were Gly, Pro and Glu.•The main elements present within jellyfish ...tissues were Cl, Na, K, Mg, S and Si.•Collagen was found to be the major protein in edible jellyfishes.
The study aimed to evaluate nutraceutical potential of three commercially significant edible jellyfish species (Acromitus hardenbergi, Rhopilema hispidum and Rhopilema esculentum). The bell and oral arms of these jellyfishes were analyzed for their proximate composition, calorific value, collagen content, amino acid profile, chemical score and elemental constituent. In general, all jellyfish possessed low calorific values (1.0–4.9kcal/g D.W.) and negligible fat contents (0.4–1.8g/100g D.W.), while protein (20.0–53.9g/100g D.W.) and minerals (15.9–57.2g/100g D.W.) were found to be the richest components. Total collagen content of edible jellyfish varied from 122.64 to 693.92mg/g D.W., accounting for approximately half its total protein content. The dominant amino acids in both bell and oral arms of all jellyfish studied includes glycine, glutamate, threonine, proline, aspartate and arginine, while the major elements were sodium, potassium, chlorine, magnesium, sulfur, zinc and silicon. Among the jellyfish, A. hardenbergi exhibited significantly higher total amino acids, chemical scores and collagen content (p<0.05) compared to R. hispidum and R. esculentum. Having good protein quality and low calories, edible jellyfish is an appealing source of nutritive ingredients for the development of oral formulations, nutricosmetics and functional food.
PDF
