Rotifer Growth Research Articles

THE EFFECT OF GIVING NATURAL FEED FROM CULTURES OF ROTIFERS (Brachionus sp.) TO GROWRTH OF WHITE SEAPER (Lates calcarifer) LARVA AND WATER QUALITY AT PT. BALI BARRAMUNDI, BULELENG DISTRICT, BALI

This research was to determine the effect of providing natural food cultures of phytoplankton and rotifers in white snapper (Lates calcarifer) hatcheries on air quality at PT. Bali Barramundi Buleleng Regency, Bali. The rotifer culture will be successful in harvesting if there is sufficient food for the rotifer zooplankton (Brachionus sp.). One good food for rotifer growth is Chlorella sp. To get 500-700 rotifers/ml for 3 weeks with an initial inoculation of 10 birds/ml requires 5 million Chlorella sp cells/ml. The air used for rotifer zooplankton is sea air which is taken directly through 3 pumps connected to pipes installed in the sea at a distance of approximately 100 meters from the shoreline. The air that has been collected is added with chlorine at a dose of 25 ppm, then after stirring thoroughly, turn off the aeration in the tub. After 1x24 hours, add sodium thiosulfate at a dose of 0.125 ppm and turn on the aeration after a while. Before being given to larvae, rotifers and enriched first using Algamax, vitamin C at a dose of 2.5g/10 L for one hour. Rotifers are given with an initial density of 4-5 ind/ml (4,000-5,000 individuals/1,000L). Natural rotifer food is given twice a day for larvae (D2-D5) at 09.00 and 15.00 and given four times a day for larvae (D6-D25) at 08.00, 10.00, 14.00, 16.00 with a dose of (5-10 tail/ml). The results of spawning showed an average hatching degree (HR) of 65% - 90.5% and normal growth up to D25 with a length of 9.5 mm. The water quality test results obtained were temperatures ranging from (28 – 30)⁰ C, pH (7.5 – 8.5), DO (6.5-6.54) ppm, salinity (28 – 36) ppt, nitrate (2.6 – 3.2) ppm, phosphate 0.01 ppm and ammonia (0.05-0.06) ppm.

Emerging threat of marine microplastics: Cigarette butt contamination on Yellow Sea beaches and the potential toxicity risks to rotifer growth and reproduction

Cigarette butts have become one of the most common and persistent forms of debris in marine coastal areas, where they pose significant toxicity risks. This study investigated cigarette butt pollution along beaches of the Yellow Sea and used laboratory experiments to assess the toxicity of their leachate and fibers on the euryhaline rotifer Brachionus plicatilis. A pollution index confirmed pollution by this debris across all eight beaches surveyed, where the density of cigarette butts averaged 0.23 butts/m2. In controlled laboratory experiments, both the fibers and leachates from cigarette butts exhibited negative impacts on the development, reproduction, and population growth of rotifers. Unique abnormalities observed under different exposure treatments indicated toxicity specific to certain chemicals and particles. Continuous exposure to cigarette butts initially reduced rotifer fecundity, but this effect diminished over successive generations. However, the exposure induced transgenerational reproductive toxicity in the rotifers. Adaptive responses in rotifers after repeated exposure led to relative reduction in reproductive inhibition in the F3 and F4 generations. Furthermore, rotifers were capable of ingesting and accumulating cigarette butts, and maternal transfer emerged as an alternative pathway for uptake of this material in the offspring. These results increase our understanding of the ecological risks posed by cigarette butts in aquatic environments.

Effects on fatty acids, biochemical composition and growth of rotifer (Brachionus plicatilis) fed with different concentrations of Nannochloropsis sp.

The density of microalgae and nutrient content have impact on the population growth rate, egg rate and nutritional values of rotifers. The aim of this study was to investigate the effects of different concentrations of the alga Nannochloropsis sp. (N10: 10x106, N20: 20x106, N30: 30x106 cells mL-1) on the growth, egg rate, biochemical composition and fatty acid profile of the rotifer Brachionus plicatilis. To maintain a consistent algae density, an equivalent quantity was supplemented to compensate for any reduction. The study was started with three replicates, each with an initial inoculation density of 200 Brachionus individuals mL-1 . The investigation spanned 5 days, during which population parameters (total number of individuals, proportion of individuals with eggs and growth rate) were calculated. After the study period, rotifers were harvested for subsequent biochemical and fatty acid analyses. Notably, the N30 group showed the highest proportions of crude protein (54.41%) and crude lipid (34.5%). The N20 group displayed the most substantial content of total fatty acids, recording a value of 70.69%. Consequently, the N30 group, with a concentration of 30x106 cells mL-1, emerged as the most proficient group, demonstrating superior performance in both population growth and biochemical composition.

L-carnitine can promote the growth performance of rotifers (Brachionus rotundiformis) by improving their feeding behavior and nutrient composition

Rotifer are important food resources in aquaculture hatcheries, and several studies have shown that L-carnitine (LC) can promote the growth performance of rotifers. The aim of this study was to investigate the nature of beneficial effects of LC on rotifer Brachionus rotundiformis. The feeding behavior of rotifers were evaluated at different LC concentrations (0, 1, 10 and 100 mg L−1). Meanwhile, the effects of LC on growth performance, free LC content, amino acid and fatty acid composition of rotifers were analyzed. The results indicated that LC (10 and 100 mg L−1) treatments significantly improved the filtration and ingestion rates of rotifers fed microalgae or baker’s yeast, In addition, LC (10 and 100 mg L−1) not only significantly accumulated in rotifers, but also significantly improved the rotifer growth performance. After 48 h of LC treatment, the rotifer population density significantly increased. Concerning the biochemical composition of rotifers, 100 mg L−1 LC can increase the carbohydrates content, decrease the protein and lipid content in the rotifers. And the LC treatment could significantly decrease the total SFA content of rotifers, while significantly increase the total HUFA content of rotifers. Moreover, the levels of LC supplementation were positively correlated with the contents of Thr, Gly, Ala, Leu, Tyr, Phe, Lys, His, Arg and Pro in rotifers. Overall, adding LC could not only accumulate in rotifers, but also promote the growth performance of rotifers by improving their feeding behavior and their nutritional value.

Population growth of two limno-terrestrial Antarctic microinvertebrates in different aqueous soil media

Terrestrial microinvertebrates provide important carbon and nutrient cycling roles in soil environments, particularly in Antarctica where larger macroinvertebrates are absent. The environmental preferences and ecology of rotifers and tardigrades in terrestrial environments, including in Antarctica, are not as well understood as their temperate aquatic counterparts. Developing laboratory cultures is critical to provide adequate numbers of individuals for controlled laboratory experimentation. In this study, we explore aspects of optimising laboratory culturing for two terrestrially sourced Antarctic microinvertebrates, a rotifer (Habrotrocha sp.) and a tardigrade (Acutuncus antarcticus). We tested a soil elutriate and a balanced salt solution (BSS) to determine their suitability as culturing media. Substantial population growth of rotifers and tardigrades was observed in both media, with mean rotifer population size increasing from 5 to 448 ± 95 (soil elutriate) and 274 ± 78 (BSS) individuals over 60 days and mean tardigrade population size increasing from 5 to 187 ± 65 (soil elutriate) and 138 ± 37 (BSS) over 160 days. We also tested for optimal dilution of soil elutriate in rotifer cultures, with 20–80% dilutions producing the largest population growth with the least variation in the 40% dilution after 36 days. Culturing methods developed in this study are recommended for use with Antarctica microinvertebrates and may be suitable for similar limno-terrestrial microinvertebrates from other regions.

Locomotory behaviour of euryhaline rotifer Brachionus rotundiformis: The potential influence of probiotics on swimming pattern and speed

AbstractWe evaluated the effect of probiotics on the growth and culture condition of rotifer in medium‐sized culture tanks. The influence of probiotics on the changes in swimming patterns, velocity and sinuosity indices of rotifer was also examined. The rotifers (Brachionus rotundiformis) were cultured for 14 days in nine polycarbonate tanks containing seawater which were divided into three groups: a control group (Chlorella product) and two treatment groups: Chlorella + Probiotic I and Chlorella + Probiotic II. The rotifer population and the water quality parameters were monitored daily. To evaluate the locomotory behaviour of the rotifer, a sub‐sample containing rotifers was obtained from each treatment and placed on a glass‐bottomed dish. A high‐speed camera mounted on a stereo microscope was used to record the rotifer movement. The footage was then analysed using motion analysis software to establish the swimming velocity, swimming pattern and sinuosity indices of the rotifers. Co‐feeding rotifer on microalgae and probiotics resulted in a higher rotifer growth rate (0.51 ± 0.03) and decreased concentration of unionized ammonia (0.14 ± 0.02 mg L−1). In addition, the probiotic‐fed rotifers had 1.59 times higher average swimming velocity (0.97 ± 0.11 mm s−1) and more straight swimming pattern compared to rotifers that fed on microalgae alone whose velocity was slow (0.61 ± 0.14 mm s−1) and more sinuous. From these data, we can postulate that probiotics have the potential to attenuate rotifer culture conditions by decreasing ammonia concentration as well as influence rotifer swimming behaviour which could affect rotifer reproduction and the quality of fish larvae in aquaculture systems.

Determination of the Optimal Conditions for the Mass Culture of Large-Type Rotifers (Brachionus plicatilis) at Low Temperatures

We aimed to determine the optimal conditions for the mass culture of rotifers, which can be used as feed for cold-water fish species at low temperatures. The growth and specific growth rates (SGRs) of rotifers were assessed considering water temperature, salinity, density, dissolved oxygen (DO) levels, and the amount of Chlorella supplied as feed. The growth of rotifers was higher at 15 °C than at 10 °C and at salinities of ~11–17 psu. Initial inoculation densities of 500 and 700 individuals/mL resulted in the highest rotifer density, and SGR was highest at 100 individuals/mL. DO concentration did not significantly affect the growth and SGRs of rotifers. Enrichment with fatty acids is important to supplement the diet of cold-water fish species. Highly unsaturated fatty acid content increased with enrichment time to 14.04 ± 0.86% at 12 h and 15.58 ± 2.20% at 24 h. Thus, the optimal conditions for rotifer mass culture are a water temperature of 15 °C, salinity of 11–17 psu, initial inoculation density of 300–500 individuals/mL, DO concentration of 8 mg/L or more, and Chlorella supply at 7.5 × 1012 cells/mL. Therefore, the present study suggests optimal culture conditions of rotifers at low temperatures for breeding cold-water fish species.

Indirect effects of invasive and native predatory copepods (Mesocyclops pehpeiensis Hu and M. longisetus curvatus Dussart) on the population growth of brachionid rotifers

Indirect effects of invasive and native predatory copepods (Mesocyclops pehpeiensis Hu and M. longisetus curvatus Dussart) on the population growth of brachionid rotifers

The potential of Lecane rotifers in microplastics removal

Dealing with hard-to-degrade plastics pollution of terrestrial and aquatic environments is one of the most urgent problems of the modern world. The smallest fraction (<5 mm) called micro-plastics (MP) has been found everywhere from ice in Greenland, streams, rivers, soil and even in the human placenta. The goal of our research was to assess the ability of rotifers Lecane inermis to remove micro-plastics suspended in the water column. In the experiments we investigated specific interactions between MP, biofilm and rotifers specialized in feeding on biofilm. We hypothesized that MP adhere to the biofilm and after ingestion by rotifers could be extracted from the water in the form of compact conglomerates excreted with fecal pellets. In these experiments, we demonstrated that: (i) the rotifers preferentially ingest microplastics embedded in biofilm, (ii) the presence of microplastics does not affect growth and fecundity of rotifers, and (iii) that MP aggregation is significantly improved by the presence of biofilm, additionally enhanced in the presence of rotifers. Our findings will help to understand the role of micro-grazers, such as L. inermis feeding on biofilm, in the fate of MP in nature. In the longer term, our results could help to develop biotechnological tools for MP removal from the aquatic environment.

Nanoplastics induce more severe multigenerational life-history trait changes and metabolic responses in marine rotifer Brachionus plicatilis: Comparison with microplastics

Micro/nanoplastics (MPs/NPs) have attracted global attention for their potential adverse impacts on marine ecosystems. This study investigated the impacts of MPs/NPs (70 nm, 500 nm, and 2 µm) on population growth and life-history traits of marine rotifer (Brachionus plicatilis), and further explored the differences from the aspects of nutrient accumulation and metabolomic profiles. The results showed that 200 and 2000 µg/L 70 nm NPs significantly suppressed population growth, and negatively affected life span, the first spawning and breeding time, and fecundity in F0–F2 generation rotifers. Whereas 500 nm NPs and 2 µm MPs showed no effect on population growth 200 µg/L and only changed the life-history traits at the highest concentration. Moreover, 70 nm NPs were more easily accumulated in the rotifers and reduced food ingestion and nutrient accumulation, which caused more severe disruption on purine-pyrimidine metabolism, tricarboxylic acid cycle, and protein synthesis pathway compared to 500 nm NPs. Thus, the smaller the size of the plastic particles, the stronger the toxicity to the rotifers. This study provided new insights into the toxicity of MPs/NPs on marine zooplankton and proposed that metabolomics was powerful to explore the toxicity mechanisms of MPs/NPs.

How nitrogen and phosphorus supply to nutrient‐limited autotroph communities affects herbivore growth: testing stoichiometric and co‐limitation theory across trophic levels

Primary producer communities are often growth‐limited by essential nutrients such as nitrogen (N) and phosphorus (P). The magnitude of limitation and whether N, P or both elements are limiting autotroph growth depends on the supply and ratios of these essential nutrients. Previous studies identified single, serial or co‐limitation as predominant limitation outcomes in autotroph communities by factorial nutrient additions. Little is known about potential consequences of such scenarios for herbivores and whether their growth is primarily affected by changes in autotroph quantity or nutritional quality. We grew a community of phytoplankton species differing in various food quality aspects in experimental microcosms at varying N and P concentrations resulting in three different N:P ratios. At carrying capacity, N, P, both nutrients or none were added to reveal which nutrients were limiting. The nutrient‐supplied communities were fed to the generalist herbivorous rotifer Brachionus calyciflorus to investigate how changing phytoplankton biomass and community composition affect herbivore abundance. We found phytoplankton being growth‐limited either by N alone (single limitation) or serially, i.e. primarily by N and secondarily by P, altering available food quantity for rotifers. Rotifer growth showed a different response pattern compared to phytoplankton, suggesting that apart from food quantity food quality aspects played a substantial role in the transfer from primary to secondary production. The combined addition of N and P to phytoplankton had generally a positive effect on herbivore growth, whereas adding non‐limiting nutrients had a rather detrimental effect probably due to stoichiometrically imbalanced food in terms of nutrient excess. Our experiment shows that adding various nutrients to primary producer communities will not always lead to increased autotroph and herbivore growth, and that differences between autotroph and herbivore responses under co‐limiting conditions can be partly well explained by concepts of ecological stoichiometry theory.

The Effect of Diffusion on the Dynamics of a Predator-Prey Chemostat Model

This paper deals with a diffusive predator-prey chemostat system which describes the growth of planktonic rotifers, Brachionus calyciflorus, feeding on unicellular green algae, Chlorella vulgaris. The dynamical behavior of this system is established in terms of the diffusion rate. The results show that there exist two critical diffusion rates which classify the dynamical behavior of this system into the following three scenarios: (i) for a large diffusion rate, all species will be washed out; (ii) for an intermediate diffusion rate, the predator goes extinct and the prey survives; (iii) for a small diffusion rate, all species coexist. Finally, our numerical results show that the solution of this system may undergo a steady-state bifurcation or Hopf bifurcation for a suitably small diffusion rate, which supplements our theoretical results.

Variations in the life-cycle parameters and population growth of rotifer Brachionus plicatilis under the stress of microplastics and 17β-estradiol

The toxic effects of microplastics (MPs) on biota are related to their particle size. In addition, MPs could adsorb ambient pollutants in water, which increase the threat of MPs to organisms. In this study, the effects of different particle sizes and concentrations of MPs on the life-cycle parameters and population growth of rotifer Brachionus plicatilis were investigated, and the combined effects of MPs and 17β-estradiol (E2) on rotifers were studied. Results showed small particle size (50 nm) MPs had negative effects on the lifespan, time to first batch of eggs, fecundity, and population growth rate of rotifers, which were dose-dependent, but large (100 nm and 500 nm) MPs were not. In addition, both life-cycle parameters and the population growth of rotifers were not affected by E2. However, the combination effects of different particle sizes of MPs and E2 on the lifespan, reproductive period, offspring per female, and population growth of rotifers were significant. Therefore, rotifers were more vulnerable to smaller particle MPs, and the coexistence of MPs and other environmental pollutants posed a serious threat to rotifers.

Mass culture of the rotifer Brachionus plicatilis under laboratory condition

In the present study the rotifer Brachionus plicatilis was cultured under controlled laboratory conditions, in Marine Science Center, Dept. of Marine Biology, the temperature was 22 ºC. The rotifers feeding on two type of food, the first was baker's yeast and second the animal manure. General, used the animal manure was better than baker's yeast. The density of rotifers culture at 22 ºC which fed on animal manure was 145 ind /ml, while growth rate was 2.67 and doubling time was 0.25 day. While, the density, growth rate and doubling time of rotifers culture at 22 ºC which fed on beakers yeast were 75 ind./ml, 2.01 and 0.34 day respectively. The importance of this study to determined the ability to depending on animal manure as cheap resource and available to improve rotifer growth compared with baker's yeast. Additional, to suitable period determined to culture of rotifer for supply it to larvae of fish and crustacean.

Species-specific ammonia tolerance in the marine rotifers Brachionus plicatilis and Brachionus rotundiformis: Reproductive characteristics and its mechanisms

High unionized ammonia (NH3−N) is a major stress factor for rearing aquatic animals that can collapse the mass culture of rotifers in aquaculture facilities. In rotifer mass culture, concentrations of NH3-N are elevated when reaching maximum density. As NH3-N toxicity has temperature-dependent characteristics, tropical and temperate rotifers should be subjected to different levels of habitat-resource NH3-N, which could affect their physiological adaptations. To investigate the NH3-N tolerance of rotifers associated with reproductive adaptations to different habitats, two rotifer species in the Brachionus plicatilis species complex were studied: temperate B. plicatilis and tropical B. rotundiformis. Survival, life history parameters, and reproductive patterns were assessed under acute (lethal) and chronic (sub-lethal) NH3-N exposure. These rotifer species were not treated with NH3-N or exposed to 1.1 and 8.5 mg/L NH3-N for 7 days to define the biochemical (i.e., oxidative and lipid metabolism) and behavioral (swimming speed) mechanisms of ammonia species sensitivity. High concentrations of NH3-N (≥8.5 mg/L) suppressed rotifer growth and reproduction, resulting in substantial maturation retardation and fecundity reduction in both species. Nevertheless, the tropical B. rotundiformis was more tolerant to acute and chronic NH3-N exposure than the temperate B. plicatilis, with 1.5 and 1.7 fold higher LC50 and EC50 (for intrinsic growth rate) values at 25 °C, respectively. Furthermore, B. rotundiformis showed stronger ammonia tolerance in sexual reproductive parameters, including mixis, fertilization, and resting egg production. High sexual reproduction tolerance is important for improving rotifer stress resistance and maintaining the population under harsh environments. The two species exhibited different modulations of lipid and stress defense activities under NH3-N exposure. Temperate B. plicatilis showed reduced neutral lipid accumulation in the reproductive organs (vitellarium/ovary), stimulated lipid peroxidation with a high level of malondialdehyde (MDA), and disrupted antioxidant activities. In contrast, the tropical B. rotundiformis exhibited active defense responses, with enhanced antioxidant activity and lipid synthesis. These findings with molecular evidence indicate the specific ammonia sensitivity between tropical and temperate rotifers, and more active anti-stress strategies of the tropical species than the temperate species, contributing to high ammonia tolerance. The higher ammonia tolerance of tropical B. rotundiformis species may support their high-density endurance during mass culture.

Use of physiological activities to estimate the population growth of rotifer (Brachionus calyciflorus) under the stress of toxic Microcystis and nitrite

Microcystis blooms disrupt aquatic systems and adversely affect zooplankton growth. Brachionus calyciflorus Pallas (rotifer) was introduced to different combinations of toxic Microcystis aeruginosa (0, 2 × 105, 2 × 106, and 2 × 107 cells mL−1) and nitrite (0, 2, 4, and 6 mg L−1) to evaluate their physiological activities and population growth under stress. Survival rate (S), population growth rate (r), grazing rate (G), antioxidant response, and metabolic and digestive enzyme activities were determined. Results revealed that G declined with the increasing nitrite doses and grazing time upon exposure to a certain Microcystis concentration. Toxic M. aeruginosa and nitrite inhibited the S, r, glutathione content, total antioxidant capacity level, and activities of alkaline phosphatase, xanthine oxidase, lactate dehydrogenase, and cellulase (p < 0.05) but increased the reactive oxygen species level, malondialdehyde content, and amylase activity (p < 0.05). The activities of superoxide dismutase, catalase, and pepsase were also increased in single low doses of nitrite solutions (p < 0.05). Therefore, the grazing intensity of rotifers affected B. calyciflorus physiological activities, which are useful in the estimation of its population growth in eutrophic water environments.

Comparison of growth performance of live feed microalgae and rotifer (Brachionus sp.) under different feeding medium in outdoor culture condition

Live feed is the basic food source and nutrient security for successful seed production of any commercially important aquaculture species of fishes, mollusks and crustaceans. Both plant and animal originated aquatic microscopic organisms are generally termed as live food. They are the basic food items in early stages (larval stage) of life cycle due to small sizes, easy digestibility and enriched in nutrients. The Nannochloropsis sp.; Nannochlorum sp. and Tetraselmis sp. are rich with relatively high content of essential fatty acids in comparison to other marine algae. Likelihood, the rotifer Brachionus sp. is ideal feed item for brackishwater finfish and mud crab larvae rearing due to its special features like rapid reproduction, slow movement, suitable size and easy digestion by the newly hatched larvae. The present study is the report on comparison of growth performance of live feed (microalgae and rotifer) in outdoor culture condition. The study was conducted at the hatchery complex of Bangladesh Fisheries Research Institute, Brackishwater Station, Paikgacha, Khulna. In outdoor culture condition the growth pattern obtained for three microalgae were Tetraselmis sp.&gt; Nannochlorum sp.&gt; Nannochloropsis sp. Highest average growth 6.87×106±1.97×106, 6.91×106±1.69×106 and 6.23×106±1.53×106 was observed for Nannochloropsis sp., Nannochlorum sp. and Tetraselmis sp. respectively in trial 3. Average growth of rotifer (Brachionus sp.) found highest 189±18.10 ind./ml at combined media of yeast and microalgae and lowest growth 119.67±17.60 ind./ml noticed with baker's yeast media. Nannochloropsis sp. contains more energy among all microalgae but Tetraselmis sp. carry highest level of protein. The highest level of protein 56.3±0.18% found in rotifer enriched with microalgae+fish oil and lowest protein content noticed with microalgae enrichment media. So, research finding suggests that, treatment T3 would be the best recommendations for rotifer culture.

L-carnitine can improve the population growth and anti-stress ability of rotifer (Brachionus rotundiformis) under ammonia stress

Rotifer Brachionus rotundiformis is the first live food for larval fish that can generally be plagued by ammonia (AC) in intensive culture systems. Ammonia accumulates enough to cause rotifer death. L-carnitine (LC) as a supplement of a vitamin-like nutrient can ameliorate rotifer growth performance and reproduction. The present study investigated the effects of LC on growth performance, antioxidant enzymatic activity, bacterial numbers and eradication of AC toxicity in rotifer. During a 7-day culture experiment added different concentration LC, Acute toxicity tests of AC and a batch culture experiment treated with LC and AC were performed. The results indicated that suitable LC concentration (1−100 mgL−1) treatment promoted significantly the rotifer population growth, while the AC was opposite and the AC median lethal concentration (LC50)-24 h was 12.24 mg L-1. Batch culture results showed that, under AC stress, LC significantly increased the rotifer population density and egg rate, and reduced rotifer malondialdehyde (MDA) level, increased rotifer Superoxide dismutase (SOD), Catalase (CAT), glutathione peroxidase (GPx) and total antioxidant capacity (T-AOC) activities. For the bacterial numbers, all treatments presented an increasing trend during the culture period, and there was a significant correlation with the rotifer population density especially in the group LC + AC. Overall, our results indicate that the rotifer growth can be inhibited by the AC, and under AC stress, LC can also improve the population growth, anti-stress ability of rotifer and the bacterial numbers in the medium. The amelioration of rotifer-growth may be linked to the anti-stress ability and the bacterial numbers.

Effects of Probiotic Fermented Kitchen Waste on the Growth and Propagation of RotiferBrachionus calyciflorus

Kitchen waste containing a large number of nutrients such as carbohydrates, proteins, lipids, and minerals can be used as fermentation substrates for producing probiotics, and then can be taken as microbial feed to cultivate rotifer. This approach not only emphasizes resource utilization of kitchen waste but also improves the growth and propagation of rotifer. In this study, kitchen wastewater and solid waste were used as fermentation substrates, respectively, while yeast, lactic acid bacteria, compound bacteria (yeast + lactic acid bacteria), and effective microorganisms (EM) bacteria were inoculated to harvest the microbial feed for the cultivation of rotifer. The population density, eggholding rate, body length, and the egg volume of rotifer were determined. These results indicate that the growth and propagation of rotifer were effectively improved by using kitchen wastewater or solid waste as fermentation substrates. When compared with the direct usage of kitchen waste for rotifer cultivation, the effect of kitchen waste fermented by probiotics on rotifer was more obvious, such as in the population density, egg-holding rate, body length, and egg volume, in the following sequence EM bacterial group &gt; yeast group &gt; compound bacterial group &gt; lactic acid bacterial group ^ control group. Hence, EM bacteria can be considered as the best one for kitchen waste fermentation to prepare microbial feed for rotifer. It is thus feasible to use probiotic fermented kitchen waste to cultivate rotifer.

The effect of different feeds on the growth, survival and reproduction of rotifer, Brachionus plicatilis

The effect of different feeds on the growth, survival and reproduction of rotifer, Brachionus plicatilis