Filamentous Microalgae Research Articles

Review on Spirulina and Health Benefit

Undernutrition is a challenge for public health, especially in developing nations. Many years ago, it was proposed to employ algae, namely spirulina, as a functional food. This was because spirulina is a high-protein food source with an amino acid profile that is thought to have a high biologic-value protein content. Free-floating filamentous microalgae that thrive in alkaline water sources are known as spirulina. In Central Africa, spirulina has been eaten for millennia due to its high nutritional content. Today, it is a commonly utilized food supplement in the area of nutraceuticals. Its therapeutic advantages on a variety of sick situations, such as hypercholesterolemia, hyperglycerolemia, cardiovascular illnesses, inflammatory diseases, cancer, and viral infections, have recently attracted a lot of attention and significant research. The main causes of spirulina's cardiovascular health advantages are its hypolipidemic, antioxidant, and anti-inflammatory properties. Information from preclinical research using different animal models Continually show that spirulina has hypolipidemic properties.

Use of plant growth regulators and their combined application to enhance lipid productivity in the filamentous microalga Tribonema sp.

Oleaginous Tribonema sp. has shown great potential in biodiesel production. However, effective strategies are still needed to increase overall lipid productivity for cost-effectiveness. Although the effects of plant growth regulators (PGRs) on enhancing microalgal growth and lipid content have been widely demonstrated, the synergistic effects of their combinations on improving lipid productivity in Tribonema sp. remain unclear. In this study, we investigated the comparative effects of five PGRs (e.g., fulvic acid, melatonin, gibberellin, γ-aminobutyric acid [GABA], and indoleacetic-3-acid [IAA]) at different concentrations (0.1–10 mg/L) on the growth, nitrogen uptake, and lipid content of Tribonema sp. The results showed that 10 mg/L GABA and 0.1 mg/L IAA were optimal conditions, contributing to an approximately 33.00 % increase in lipid productivity compared with the control (without PGRs). Based on these findings, the combination of optimized concentrations of GABA and IAA, especially in equal proportions, resulted in a more desirable fatty acid profile and produced the highest biomass, lipid content, and lipid productivity, with increases of 23.55 %, 25.62 %, and 54.95 %, respectively, over the control. This combination also significantly increased nitrogen removal efficiency in the medium, which was 46.24 % higher that of the control. These results were attributed to the significant upregulation of genes associated with nitrogen metabolism mediated by the synergy of IAA and GABA, promoting nitrate uptake by algal cells in the medium. Genes involved in photosynthesis and lipid synthesis were also upregulated, facilitating simultaneous biomass and lipid accumulation to maximize lipid productivity. Overall, this study is the first to report the combined application of GABA and IAA as an effective strategy to enhance lipid productivity in Tribonema sp., providing insights into the underlying mechanisms. These findings offer a promising solution for economically improving microalgal lipid production.

Unveiling potential of promising filamentous microalga Klebsormidium cf. nitens: Shear stress resilience and carotenoid-fatty acid dynamics in tubular photobioreactor

In this study, the effects of shear stress and different culture media on the growth of the filamentous microalga Klebsormidium cf. nitens were studied. The microalga’s growth, carotenoids and fatty acids were further evaluated in a pump-driven tubular photobioreactor. The results show that this microalga had the ability to withstand high shear stress and the adaptability to grow in a culture medium that lacks certain trace elements. K. cf. nitens grew consistently in the tubular photobioreactor at different average light intensities although it did not grow well in a tall bubble column. The carotenoid analysis revealed that the xanthophyll cycle was activated to protect the cell photosynthetic system. The fatty acids increased with irradiance, with linoleic acid (C18:2n6) making up over 50 % of the total fatty acids. This study supports the potential of employing pump-driven tubular photobioreactors to produce the filamentous microalga K. cf nitens at the large scale.

Lipid-extraction of Tribonema minus avoids foaming facilitating anaerobic co-digestion with molasses vinasse

Tribonema minus, a filamentous microalgae, has great potential as an anaerobic digestion (AD) substrate, owing to its relatively low cultivation and harvesting costs. This is the first study to explore the effect of T. minus as an anaerobic co-digestion (AcoD) substrate with molasses vinasse (MV). To analyze the potential effects of the structure and composition of T. minus on the AD process, we conducted batch and semi-continuous AD using simple dehydrated T. minus (Fresh T. minus, FTR) and lipid-extracted and pulverized T. minus (Pretreated-T. minus, PTR). The results showed that the maximum methane production potential of FTR was 158.9 ± 2.9 mL CH4 g−1 VS, which was reduced by 25% after pretreatment. However, the methane production potential increased by 18% in the batch AcoD with MV. Meanwhile, FTR led to the accumulation of fatty acids and lipids, including palmitic acid, in semi-continuous AcoD with MV. Lipid accumulation further increased the polysaccharide and protein content in the extracellular polymeric substances, resulting in a decrease in liquid surface tension and an increase in foam formation, which ultimately led to a decrease in methane production potential and soluble chemical oxygen demand removal rate. Microbial community analysis demonstrated that PTR effectively mitigated the inhibitory effects caused by filamentous microalga (FM). Our results further elucidated the potential mechanism of foam formation during the AD of FTR and revealed that pretreatment can lead to effective recovery of products from T. minus while promoting methane production potential and optimizing the microbial community composition during AcoD. Therefore, our study provides novel insights into the utilization of FM.

A Potent Mixture Of Antioxidants In Spirulina Have Numerous Advantages For Human Health

Spirulina is a free-floating filamentous microalga that grows in alkaline water. Spirulina was consumed as food by the Mayas, Toltecs, and Kanembu in Mexico during the Aztec civilization approximately 400 years ago. Spirulina is a well-known source of essential nutrients such as proteins, vitamins, amino acids, minerals, fatty acids, and so on. It's popular in human and animal nutrition, as well as the cosmetics business. In vivo and in vitro experiments have yielded promising results in the treatment of certain malignancies and allergies, anaemia, hepatotoxicity, viral infection, vascular disorders, radiation protection, and obesity. Spirulina's antioxidant effects have been proven in numerous preclinical research. Antioxidants aid in the prevention of many human diseases.

Microbial Diversity and Community Structure of Wastewater-Driven Microalgal Biofilms.

Dwindling water sources increase the need for efficient wastewater treatment. Solar-driven algal turf scrubber (ATS) system may remediate wastewater by supporting the development and growth of periphytic microbiomes that function and interact in a highly dynamic manner through symbiotic interactions. Using ITS and 16S rRNA gene amplicon sequencing, we profiled the microbial communities of four microbial biofilms from ATS systems operated with municipal wastewater (mWW), diluted cattle and pig manure (CattleM and PigM), and biogas plant effluent supernatant (BGE) in comparison to the initial inocula and the respective wastewater substrates. The wastewater-driven biofilms differed significantly in their biodiversity and structure, exhibiting an inocula-independent but substrate-dependent establishment of the microbial communities. The prokaryotic communities were comparable among themselves and with other microbiomes of aquatic environments and were dominated by metabolically flexible prokaryotes such as nitrifiers, polyphosphate-accumulating and algicide-producing microorganisms, and anoxygenic photoautotrophs. Striking differences occurred in eukaryotic communities: While the mWW biofilm was characterized by high biodiversity and many filamentous (benthic) microalgae, the agricultural wastewater-fed biofilms consisted of less diverse communities with few benthic taxa mainly inhabited by unicellular chlorophytes and saprophytes/parasites. This study advances our understanding of the microbiome structure and function within the ATS-based wastewater treatment process.

Potential Protective Effects of Spirulina (Spirulina platensis) against In Vitro Toxicity Induced by Heavy Metals (Cadmium, Mercury, and Lead) on SH-SY5Y Neuroblastoma Cells

Spirulina, a filamentous microalga, is used all over the world as a nutraceutical dietary supplement. Recent studies have focused on examining its chelating activity and antioxidant properties, especially as a candidate for protection against neurotoxicity caused by heavy metals. The MTT test and LDH assay were used to examine the viability of the SH-SY5Y cells for 24, 48, and 72 h, to Cd, Hg, and Pb, individually or in combination with Spirulina, and the effects of necrotic cell death. In comparison to the control group, the viability of SH-SY5Y cells decreased after 24 h of exposure, with Cd being more toxic than Hg and Pb being less lethal. The effects of heavy metal toxicity on cell survival were ranked in order after 72 h under identical experimental circumstances as follows: Hg, Pb, and Cd. The viability of the cells was then tested after being exposed to Spirulina at doses of 5 at 50 (%v/v) for 24, 48, and 72 h, respectively. SH-SY5Y cells that had been treated with mixtures of heavy metals and Spirulina underwent the same assay. Cell viability is considerably increased by using Spirulina treatments at the prescribed periods and doses. Instead, the same procedure, when applied to SH-SY5Y cells, caused the release of LDH, which is consistent with the reduction in cell viability. We demonstrated for the first time, considering all the available data, that Spirulina 5, 25, and 50 (%v/v) enhanced the number of viable SH-SY5Y cells utilized as a model system for brain cells. Overall, the data from the present study provide a first insight into the promising positive role of Spirulina against the potentially toxic effects of metals.

Advanced treatment and Resource recovery of brewery wastewater by Co-cultivation of filamentous microalga Tribonema aequale and autochthonous Bacteria

To use unicellular microalgae to remove waste nutrients from brewery wastewater while converting them into algal biomass has been explored but high-cost treatment and low-value biomass associated with current technologies have prevented this concept from further attempts. In this study, a filamentous microalga Tribonema aequale was introduced and the alga can grow vigorously in brewery wastewater and algal biomass concentration could be as high as 6.45 g L−1 which can be harvested by a cost-effective filtration method. The alga together with autochthonous bacteria removed majority of waste nutrients from brewery wastewater. Specifically, 85.39% total organic carbon (TOC), 79.53% total dissolved nitrogen (TN), 93.38% ammonia nitrogen (NH3–N) and 71.33% total dissolved phosphorus (TP) in brewery wastewater were rapidly removed by co-cultivation of T. aequale and autochthonous bacteria. Treated wastewater met the national wastewater discharge quality, and resulting algal biomass contained large amounts of high-value products chrysolaminarin, palmitoleic acid (PLA) and eicosapentaenoic acid (EPA). It is anticipated that reduced cost of algal harvesting coupled with value-added biomass could make T. aequale as a promising candidate for brewery wastewater treatment and resource utilization.

Fossils, pseudofossils and problematica from the Ura Formation: Ediacaran of the Patom Basin, Siberia

The pseudofossils, problematica and actual macrofossils from the Middle Ediacaran Ura Formation of the Patom Basin of Siberia are critically reviewed. Both the pseudofossils and problematica are flat-clasts of ooid grainstones that are interpreted as a product of submarine gravitational or storm-induced erosional episodic events. Some extremely flat batten-shaped ooid and cementstones 2D-clasts closely resemble shreds of ribbon-like macrophyte phytoleims randomly scattered on a bedding plane. They can potentially be considered as a cement-incrustation along the algae thalli buried within ooid sands or shales, however, there is no certainty in their taxonomic identification. At the same time, other abiotic or microbially induced formation mechanisms of these fragments cannot be excluded. The Ura macrofossils, similar in size to the 2D-clasts, are described from the same outcrop, approximately 60 m downsection. They are represented mainly by the ribbon-shaped carbonaceous compressions of Liulingjitaenia alloplecta that demonstrate the stratigraphically lowest appearance of the Miaohe-type fossils in mid-Ediacaran (pre-Shuram, 580–570 Ma) strata of Ura Formation in close association with Doushantuo-type acanthomorphic acritarchs. These fossils are present as a detrital component or as in situ buried large (decimeter scale) colonial clusters. The colonies covered significant surface areas of the soft muddy sea-floor beneath wave-base. L. alloplecta themselves, commonly attributed to green macroalgae, could also be considered as composite colonies of filamentous microalgae or cyanobacteria.

Isolation and characterization of soil cyanobacteria and microalgae and evaluation of their potential as plant biostimulants

Background and AimsBiocrusts are found on soil surface resulting from an association between soil particles and microorganisms. Photoautotrophic cyanobacteria and microalgae are pioneers on biocrusts formation, promoting soil stability, nutrients availability and water retention, leading to the development of other communities. This work aimed at isolating and characterizing cyanobacteria/microalgae from biocrusts (Central Portugal) and to assess their potential as plant biostimulants, as well as obtaining an insight into their mechanism(s) of action.MethodsMicroorganisms were isolated through successive spread plating/serial dilutions and characterized using genetical analysis/morphological traits. An initial screening was performed using exudates from each microorganism and two plant species, Arabidopsis thaliana and Lolium multiflorum. Subsequently, the selected microorganisms were tested as a consortium in hydroponic systems. Biometric and biochemical parameters were evaluated for both plant species.ResultsThe consortium microorganisms belong to genera often found in soils/biocrusts: Trichocoleus, Nodosilinea, Microcoleus (filamentous cyanobacteria), Nostoc (diazotrophic heterocystous cyanobacteria), and Klebsormidium (filamentous microalga), and some of them have the capacity to produce phytohormones and/or siderophores. The consortium showed biostimulant potential in hydroponic cultures, promoting plant growth and enhancing physiological productivity related parameters. Stress related parameters revealed that the microorganisms did not lead to a stressful situation. However, a significant increase in proline was observed, endorsing a role of this molecule in this process.ConclusionThis study contributes to the knowledge on the biodiversity of cyanobacteria and microalgae from Portuguese soils and highlights their potential as biostimulants, constituting a step forward towards understanding the molecular mechanisms behind this effect.

Effects of sodium selenite on the growth, biochemical composition and selenium biotransformation of the filamentous microalga Tribonema minus

This study aimed to investigate the physiological and biochemical responses of filamentous microalga Tribonema minus to different Na2SeO3 concentrations and its selenium absorption and metabolism to evaluate the potential in treating selenium-containing wastewater. The results showed that low Na2SeO3 concentrations promoted growth by increasing chlorophyll content and antioxidant capacity, whereas high concentrations caused oxidative damage. Although Na2SeO3 exposure reduced lipid accumulation compared with the control, it significantly increased carbohydrate, soluble sugar, and protein contents, with the highest carbohydrate productivity of 117.97 mg/L/d at 0.5 mg/L Na2SeO3. Furthermore, this alga effectively absorbed Na2SeO3 in the growth medium and converted most of it into volatile selenium and a small part into organic selenium (predominantly as selenocysteine), showing strong selenite removal efficacy. This is the first report on the potential of T. minus to produce valuable biomass while removing selenite, providing new insights into the economic feasibility of bioremediation of selenium-containing wastewater.

Characterization and evaluation of substratum material selection for microalgal biofilm cultivation

Biofilm cultivation is considered a promising method to achieve higher microalgae biomass productivity with less water consumption and easier harvest compared to conventional suspended cultivation. However, studies focusing on the selection of substratum material and optimization of the growth of certain microalgae species on specific substratum are limited. This study investigated the selection of membranous and fabric fiber substrata for the attachment of unicellular microalgae Scenedesmus dimorphus and filamentous microalgae Tribonema minus in biofilm cultivation. The results indicated that both algal species preferred hydrophilic membranous substrata and nitrate cellulose/cellulose acetate membrane (CN-CA) was selected as a suitable candidate on which the obtained biomass yields were up to 10.24 and 7.81gm-2day-1 for S. dimorphus and T. minus, respectively. Furthermore, high-thread cotton fiber (HCF) and low-thread polyester fiber (LPEF) were verified as the potential fabric fiber substrata for S. dimorphus (5.42gm-2day-1) and T. minus (5.49gm-2day-1) attachment, respectively. The regrowth of microalgae biofilm cultivation strategy was applied to optimize the algae growth on the fabric fiber substrata, with higher biomass density and shear resistibility achieved for both algal species. The present data highlight the importance to establish the standards for selection the suitable substratum materials in ensuring the high efficiency and sustainability of the attached microalgal biomass production. KEY POINTS: • CN-CA was suitable membranous substratum candidate for algal biofilm cultivation. • HCF and LPEF were potential fabric fiber substrata for S. dimorphus and T. minus. • Regrowth biofilm cultivation was effective in improving algal biomass and attachment.

The growth, lipid accumulation and adaptation mechanism in response to variation of temperature and nitrogen supply in psychrotrophic filamentous microalga Xanthonema hormidioides (Xanthophyceae)

BackgroundMicroalgae are promising feedstocks for production of renewable biofuels and value-added bioproducts. Temperature and nitrogen supply are important environmental and nutritional factors affecting the growth and metabolism of microalgae, respectively. In this study, the growth and lipid accumulation of filamentous microalgae Xanthonema hormidioides under different temperatures (5, 7, 10, 15, 20, 25, 27 and 30 °C) and initial nitrogen concentrations (3, 9, 18 mM) were investigated, and its adaptive mechanisms of tolerance to low temperature and nitrogen stress were analysis by proteomics.ResultsThe optimum temperature range for the growth of X. hormidioides was between 15 and 20 °C, and the algal cells had slow growth rate at 5 °C and could not survive at 30 °C. The maximum biomass concentration was 11.73 g L−1 under the temperature of 20 °C, and the highest total lipid content was 56.63% of dry weight. Low temperature did not change the fatty acids profiles but promoted the accumulation of unsaturated fatty acids of X. hormidioides. The maximum contents of palmitoleic acid, eicosapentaenoic acid and total fatty acid were 23.64%, 2.49% and 41.14% of dry weight, respectively. Proteomics was performed under three temperature (7, 15, 25 °C), two nitrogen concentrations (3 and 18 mM) and two cultivation times (day 3 and 12). A total of 6503 proteins were identified. In the low temperature, photosynthesis-related proteins were down-regulated to protect the photosynthetic apparatus. The up-regulation of key enzymes DGAT and PDAT demonstrated the accumulation of TAGs under low nitrogen treatment. The proteins related to ribosome, phosphatidylinositol signaling system, antioxidant system and cold shock proteins (CSPs) in X. hormidioides were co-upregulated under the treatment of low temperature, which can alleviate the damages induced by temperature stress and maintain the normal growth and metabolism of algal cells.ConclusionsX. hormidioides is a psychrotolerant microalga. It is an oleaginous filamentous microalga containing hyper palmitoleic acid and a certain amount of eicosapentaenoic acid with great potential for biofuel development, as well as for applications in nutritional health products and other industries.

Using carbon dioxide-added microalgal-bacterial granular sludge for carbon-neutral municipal wastewater treatment under outdoor conditions: Performance, granule characteristics and environmental sustainability

Microalgal-bacterial granular sludge (MBGS) process has a gorgeous prospect for municipal wastewater treatment, but the research on the treatment of complex organic wastewater by MBGS process with CO2 addition under outdoor conditions is not enough. Therefore, this paper evaluated the feasibility of CO2-added MBGS process for complex organic wastewater disposal under natural day-night cycles. The results showed that the addition of CO2 overall improved the removal efficiency of pollutants. Typically, the removal efficiency of total phosphorus increased averagely from 88.5 % to 95.0 % in 12-h day cycle and from 26.2 % to 45.3 % in 12-h night cycle. The addition of CO2 increased the size of MBGS from 1.0 mm to 16.5 mm within 30 days due to extracellular polymeric substances secretion and the dominant filamentous microalgae on granules. The decrease of catalase activity and malondialdehyde content indicated that CO2 reduced oxidative damage and maintained the normal growth of MBGS. Further estimates of the collected gas showed that CO2-added MBGS process could reduce global CO2 emissions by one hundred million tons per year. This study is expected to contribute to the goal of carbon neutrality in the area of wastewater treatment by MBGS process.

Effects of Barranca yajiagengensis Powder in the Diet of Trachinotus ovatus on the Growth Performance, Antioxidant Capacity, Immunity and Morphology of the Liver and Intestine.

Barranca yajiagengensis, a novel filamentous microalga, can accumulate lutein under high-light and low-nitrogen conditions. It is well known that lutein has antioxidant, anti-inflammatory and immune-modulating properties. The purpose of this study is to evaluate the effects of including lutein-rich B. yajiagengensis powder in the diet of Trachinotus ovatus on the growth performance, antioxidant capacity, immunity, liver, and intestinal morphology. For this aim, three experimental diets containing 0% (BY0), 1% (BY1), and 5% (BY5) B. yajiagengensis powder were formulated for six-week feeding trials. The results indicated that growth performance, feed utilization, and intestinal morphology were not affected by different diet treatments. Fish fed with the BY5 diet promoted antioxidant ability by activating the Nrf2-ARE signal pathway and enhancing antioxidant enzymes activities. Furthermore, the BY5 diet improved non-specific immunity and antibacterial ability by activating lysozymes and the complement system and increasing the nitric oxide (NO) content and total nitric oxide synthase activity. Dietary B. yajiagengensis supplementation improved the liver morphology and exerted hepatoprotective effects. Therefore, as a natural source of lutein, B. yajiagengensis has the potential as a safe and non-toxic immunostimulant for T. ovatus. A diet supplemented with 5% B. yajiagengensis is recommended to improve the growth, antioxidant capacity, immune response, and liver health of T. ovatus.

Optimization of Microalgae–Bacteria Consortium in the Treatment of Paper Pulp Wastewater

The microalgae–bacteria consortium is a promising and sustainable alternative for industrial wastewater treatment, since it may allow good removal of organic matter and nutrients, as well as the possibility of producing products with added value from the algae biomass. This research investigated the best bacterial and microalgae inoculation ratio for system start-up and evaluation of removing organic matter (as chemical oxygen demand (COD)), ammoniacal nitrogen (NH4+–N), nitrite nitrogen (NO2−–N), nitrate nitrogen (NO3−–N), phosphate phosphorus (PO43−–P) and biomass formation parameters in six photobioreactors with a total volume of 1000 mL. Reactors were operated for 14 days with the following ratios of pulp mill biomass aerobic (BA) and Scenedesmus sp. microalgae (MA): 0:1 (PBR1), 1:0 (PBR2), 1:1 (PBR3), 3:1 (PBR4), 5:1 (PBR5), and 1:3 (PBR6). Results show that COD removal was observed in just two days of operation in PBR4, PBR5, and PBR6, whereas for the other reactors (with a lower rate of initial inoculation) it took five days. The PBR5 and PBR6 performed better in terms of NH4+–N removal, with 86.81% and 77.11%, respectively, which can be attributed to assimilation by microalgae and nitrification by bacteria. PBR6, with the highest concentration of microalgae, had the higher PO43−–P removal (86%), showing the advantage of algae in consortium with bacteria for phosphorus uptake. PBR4 and PBR5, with the highest BA, led to a better biomass production and sedimentability on the second day of operation, with flocculation efficiencies values over 90%. Regarding the formation of extracellular polymeric substances (EPS), protein production was substantially higher in PBR4 and PBR5, with more BA, with average concentrations of 49.90 mg/L and 49.05 mg/L, respectively. The presence of cyanobacteria and Chlorophyceae was identified in all reactors except PBR1 (only MA), which may indicate a good formation and structuring of the microalgae–bacteria consortium. Scanning electron microscopy (SEM) analysis revealed that filamentous microalgae were employed as a foundation for the fixation of bacteria and other algae colonies.

Assessment of Eicosapentaenoic Acid (EPA) Production from Filamentous Microalga Tribonema aequale: From Laboratory to Pilot-Scale Study.

It has long been explored to use EPA-rich unicellular microalgae as a fish oil alternative for production of the high-value omega-3 fatty acid eicosapentaenoic acid (EPA, 20:5, n-3). However, none of the efforts have ever reached commercial success. This study reported a filamentous yellow-green microalga Tribonema aequale that possesses the ability to grow rapidly and synthesize significant amounts of EPA. A series of studies were conducted in a glass column photobioreactor under laboratory culture conditions and in pilot-scale open raceway ponds outdoors. The emphasis was placed on the specific nutrient requirements and the key operational parameters in raceway ponds such as culture depth and mixing regimes. When optimized, T. aequale cells contained 2.9% of EPA (w/w) and reached a very high biomass concentration of 9.8 g L−1 in the glass column photobioreactor. The cellular EPA content was increased further to 3.5% and the areal biomass and EPA productivities of 16.2 g m−2 d−1 and 542.5 mg m−2 d−1, respectively, were obtained from the outdoor pilot-scale open raceway ponds, which were the record high figures reported thus far from microalgae-based EPA production. It was also observed that T. aequale was highly resistant to microbial contamination and easy for harvesting and dewatering, which provide two additional competitive advantages of this filamentous microalga over the unicellular counterparts for potential commercial production of EPA and other derived co-products.

Dietary Klebsormidium sp. Supplementation Improves Growth Performance, Antioxidant and Anti-Inflammatory Status, Metabolism, and Mid-Intestine Morphology of Litopenaeus Vannamei.

Filamentous microalga Klebsormidium sp. has huge potential to become a natural and healthy additive in aquatic feed since it contains various bioactive nutrients, such as linoleic acid (LA), carotenoids, and chlorophylls. Therefore, an eight-week feeding experiment was performed to evaluate the effects of dietary Klebsormidium sp. on the growth performance, antioxidant and anti-inflammatory status, metabolism, and mid-intestine morphology of Litopenaeus vannamei. Two isonitrogenous and isolipid diets supplemented with and without 5% Klebsormidium sp. were prepared. Results showed that L. vannamei fed with Klebsormidium sp. had better growth performance and feed utilization by optimizing mid-intestine morphology and improving the carbohydrate metabolism. In addition, Klebsormidium sp. also enhanced the antioxidant capacity of L. vannamei by downregulating antioxidant parameters (hepatopancreas T-SOD, hepatopancreas GSH-PX, hemolymph T-SOD, hemolymph MDA) and RNA expression levels of antioxidant genes (gsh-px and cat). Furthermore, the supplementations of dietary Klebsormidium sp. significantly improved hepatopancreas health by downregulating RNA expression levels of pro-inflammatory related genes (relish and rho). Therefore, a dose of 5% Klebsormidium sp. is recommended for the daily diet of L. vannamei to improve the growth performance, antioxidant and anti-inflammatory status, metabolism, and mid-intestine morphology of shrimp.

Therapeutics role of spirulina platensis in disease prevention and treatment

Spirulina are multicellular and filamentous blue-green microalgae belonging to two separate genera Spirulina and Arthrospiraand consists of about 15 species. Of these, Arthrospira platensis is the most common and widely available spirulina and most of the published research and public health decision refers to this specific species. It grows in water, can be harvested and processed easily and has significantly high macro- and micronutrient contents. In many countries of Africa, it is used as human food as an important source of protein and is collected from natural water, dried and eaten. It has gained popularity in the human health food industry and in many countries of Asia it is used as protein supplement and as human health food. Spirulina has been used as a complementary dietary ingredient of feed for poultry and increasingly as a protein and vitamin supplement to aqua feeds. Spirulina can play an important role in human and animal nutrition, environmental protection through waste water recycling and energy conservation. Spirulina is free floating filamentous microalgae growing in alkaline water bodies The present review was focused on the various characteristics of Spirulina platensisSpirulina is rich in proteins (60-70%), vitamins and minerals used as protein supplement in diets of undernourished poor children in developing countries. One gram of Spirulina protein is equivalent to one kilogram of assorted vegetables. The amino acid composition of Spirulina protein ranks among the best in the plant world, more than that of soya bean. The mass cultivation of Spirulina is achieved both in fresh water and waste water. Spirulina grown in clean waters and under strictly controlled conditions could be used for human nutrition. The micro algae gown in waste water is used as animal feed and provide a source of the fine chemicals and fuels. The waste water system is highly applicable in populated countries like India where wastes are generated in high quantities and pose environmental problem.

Seasonal and interannual variability of feeding in Antarctic benthos

AbstractThe seasonal and interannual variability of feeding in 15 species of benthic marine suspension feeder was studied over 8 yr at Ryder Bay, Antarctica. Feeding was strongly seasonal in bryozoans, gorgonians, polychaetes, and dendrochirote holothurians. The winter non‐feeding period was longest in the holothurians and shortest in bryozoans. Bryozoans started feeding in late winter at very low chlorophyll concentrations, often when surface fast‐ice was still present. In hydroids and actinians, feeding tentacles were deployed continuously throughout the year, though hydroid feeding intensity declined slightly in late winter. Water column phytoplankton biomass was strongly seasonal with marked interannual variability in the timing and intensity of the bloom, driven principally by ice dynamics. Correlation across years between the start of feeding and the development of the bloom was poor, and in seasons when a dense spring bloom of benthic filamentous microalgae developed, the start of feeding in many benthic species was delayed. This study indicates that feeding in benthic marine suspension feeders in Antarctica is influenced by factors additional to the seasonal availability of food in the water column.