Specific Growth Rate Research Articles

The effect of continuous and pulse feeding Lactiplantibacillus plantarum on growth performance, gut microbiota, immunological, haematological and plasma biochemical parameters of rainbow trout Oncorhynchus mykiss

A potentially probiotic autochthonous strain of Gram-positive lactic acid bacteria, Lactiplantibacillus plantarum R2 Biocenol™ (CCM 8674), was assessed as a feed supplement in rainbow trout Oncorhynchus mykiss. Three treatment groups were compared; control, fish provided L. plantarum as a four-week dietary pulse followed by three weeks of non-supplemented diet and fish provided the supplemented feed for seven weeks. A trend of improved growth performance (specific growth rate, feed conversion ratio) was observed in both supplemented groups. Though the effect of pulse supplementation on the intestinal microbiome community was not permanent, a statistically significant difference was recorded in the composition of the gut content bacterial community in both pulse and continuous supplemented groups. A significant reduction in the abundance of several bacterial genera was observed in the gut microbiome of fish given the seven-week supplementation. Continuous supplementation significantly increased blood haemoglobin and haematocrit levels and reduced plasmatic chloride concentration, while significantly increased concentrations of plasmatic magnesium and calcium were recorded in pulse-fed fish. No significant changes in immunological indices were revealed. Our results suggest that four weeks and seven weeks supplementation of L. plantarum show similar trends of effects on growth performance in rainbow trout. Further studies will follow to assess the effects of L. plantarum R2 Biocenol™ on the response of rainbow trout to a pathogens challenge in relation to the change in gut microbiome composition.

Therapeutic Effect of Dietary Turmeric (Curcuma longa) on Growth Performance, Hematology Profile and Immunity Parameters of Common Carp (Cyprinus carpio)

Medicinal plants are rich in diverse nutrients and antioxidants that promote growth and have immunostimulating activities for fish. In aquaculture phytomedicines have gained importance worldwide because they are easily available, non-toxic to aquatic life. Turmeric (Curcuma longa) is among the most suitable natural ingredient due to its biological effects. Therefore, a study has been conducted to determine the effect of turmeric on the growth performance, hematology and immunity of common carp Cyprinus carpio. For this purpose, 180 fingerlings of common carp with average initial weight (30.23±0.04 g) were divided into six groups containing five treatment groups. Each tank was stocked with 10 fingerlings. Treatments were maintained in triplicates. Fish were fed with basal diet supplemented with graded level of turmeric at different concentrations i.e. TE0 (control), TE1 (1.0%), TE2 (2.0%), TE3 (3.0%), TE4 (4.0%) and TE5 (5.0%). Fish were fed twice a day at 3% body weight for 12 weeks. Results showed that fish growth was higher in all treatments as compared to the control group. The feed efficiency ratio (FER), feed conversion ratio (FCR), specific growth rate (SGR) and condition factor (K), of fish fed with turmeric enriched diet were found to be better than the control group. TE4 diet exposed to 4% Turmeric, showed maximum growth in terms of growth performance and feed utilization. Moreover, haematology profile and immunity parameters also improved by turmeric supplementation. The result of the present study shows that turmeric has the potential to enhance the growth performance of common carp. Overall, the TE4 % dietary group showed better growth performance and immunity than the control group and other treated groups.

AM fungus plant colonization rather than an Epichloë endophyte attracts fall armyworm feeding.

Most cold-season grasses can be colonized by belowground arbuscular mycorrhizal (AM) fungi and foliar grass endophytes (Epichloë) simultaneously while also be attacked by insect herbivores. The colonization of AM fungi or the presence of grass endophytes is associated with increased resistance by the host plant. However, studies on how these two symbionts affect host plants and mitigate insect pest attack are currently lacking. In a glasshouse study we investigated the effects of an AM fungus (Acaulospora delicata), a foliar grass endophyte (Epichloë), and the insect pest Spodoptera frugiperda (fall armyworm, FAW) on plant growth, defense enzyme activity, and hormone concentrations of the important pasture grass Lolium perenne. Additionally, we assessed the selective behavior of FAW larvae in response to these interactions using olfactometer tests. Our results showed that the AM fungus and its co-colonization with Epichloë endophytes increased aboveground biomass, while Epichloë endophytes alone had no significant impact on ryegrass aboveground biomass. In contrast, FAW reduced aboveground biomass. The Epichloë endophytes and FAW significantly decreased the mycorrhizal colonization rate by 21.67% and 30.16%, respectively. Interestingly, compared to non-mycorrhizal plants, AM fungus colonized plants were more attractive to FAW larvae feeding, and the defense enzyme activity was not discernibly affected by any experimental treatments. The interactions of the AM fungus and Epichloë endophyte increased the jasmonic acid concentrations by 24.29% and decreased trasylol activity by 11.75% in the host plants under FAW attack. Neither the AM fungus nor Epichloë endophyte influenced the relative growth rate (RGR) of FAW. Overall, the AM fungus had a greater positive effect on plant growth than the Epichloë endophyte, regardless of FAW larvae infestation.

Net Assimilation Rate and Mean Relative Growth Rate of Horticulture Plants on Swamp Land under Control of Organic Compounds

This research involved two experiments and was conducted in the experiment station of Faculty of Agriculture, Islamic University of Riau, Indonesia. This experiment was arranged with a randomly simple design with two factors. First, the effects of water hyacinth (Eichhornia crassipes) compost and rice husk ash on Brassica juncea, and secondly the effects of water hyacinth compost and Rhizobium inoculant on soybean (Glycine max) were investigated. The data analysis was performed with Duncan’s multiple range test with significant differences at p <0.05. The net assimilation rate and mean relative growth rate were used as indicators for the dry weight accumulation of plants. The combination of water hyacinth compost and rice husk ash had an interacting effect on soybean and Brassica juncea. An increase of net assimilation rate was followed by an increase in mean relative growth and a significant increase in dry matter weight was also observed. A combination of water hyacinth compost and rice husk ash had a significant positive effect on plant growth in swamp land. Rice husk ash can potentially balance excess iron and aluminum levels in soil impedes the absorption of essential minerals in swamp land. Rice husk ash can potentially balance excess iron and aluminum levels in soil that impedes the absorption of essential minerals in swamp land. The combination of water hyacinth compost and rice husk ash in swamp land increased the production of seed dry weight of soybean and crop dry weight of Brassica juncea.

Mitigating Vibrio-Induced Skin Ulceration in Sea Cucumbers Using Probiotic Strains

Sea cucumbers are valuable in aquaculture, but their cultivation faces challenges from diseases such as skin ulceration syndrome caused by Vibrio alginolyticus (VA). This study aimed to isolate and identify probiotics capable of combating VA and improving sea cucumber’s growth performance. Pathogenic VA was identified, through 16S rDNA sequencing, confirming its high genetic similarity (>99%) to Vibrio alginolyticus. Two Bacillus strains, Bacillus licheniformis YB-1, and Bacillus megaterium YB-2, were isolated as potential probiotics, with identification supported by 16S rDNA phylogenetic analysis and deposition in microbial culture collections. They demonstrated strong antibacterial activity against VA in vitro without exhibiting antagonism when combined. Probiotic tolerance to environmental stressors was observed, while feeding trials revealed significant growth improvements in sea cucumbers, with the highest specific growth rates observed at 1 × 106 CFU/mL for both strains. Immersion challenge tests showed that sea cucumbers treated with probiotics exhibited reduced symptoms of rotten skin syndrome and higher survival rates. The optimal combination of YB-1 and YB-2, with viable bacteria concentrations of 5 × 107 CFU/mL each, achieved a 55% survival rate after a VA challenge, demonstrating their synergistic efficacy. These findings suggest that YB-1 and YB-2 offer promising probiotic solutions for enhancing sea cucumber health and resistance to VA infections in aquaculture.

Effect of Feeding Frequency on the Growth, Body Composition, and Intestinal Health of Hybrid Grouper (Epinephelus fuscoguttatus♀ × E. lanceolatu♂) Fed a High-Fat Diet

This experiment was to investigate the effects of feeding frequency on the growth performance, body composition, and intestinal health of hybrid grouper (Epinephelus fuscoguttatus♀ × E. lanceolatu ♂). Fifty-six days of feeding with four different feeding frequencies (1 time/day, 2 times/day, 3 times/day, and 4 times/day) were conducted on groupers with an initial body weight of 11.51 ± 0.02 g. The results show the following: (1) Weight gain rate (WGR) and specific growth rate (SGR) of the groupers in the 1 time/day group were significantly lower than in other groups (p < 0.05). (2) Superoxide dismutase (SOD) had the lowest value in the 1 time/day group, significantly lower than the 2 times/day and 4 times/day groups, catalase showed an upward trend, and the 4 times/day group was significantly greater than the other groups (p < 0.05). The total antioxidant capacity (T-AOC) and glutathione peroxidase (GPX) activities in the 1 time/day group were significantly lower than in the other groups (p < 0.05). (3) The increase in feeding frequency led to a significant increase in the expression levels of cat and il-6 (p < 0.05). In summary, appropriate feeding frequency can promote growth and enhance the antioxidant capacity of the fish’s gut. We recommend a best feeding frequency of 2 times/day.

Survival and growth of three boreal conifer species transplanted to warm sites: Implications for responses to global warming and extreme climatic events

Understanding the responses of boreal conifers to climate change are essential for future mitigation and adaptation. In this study, three-year-old seedlings of three Japanese boreal conifers including Sakhalin fir, Yezo spruce, and Sakhalin spruce, naturally found in Hokkaido, Japan, were transplanted in spring 2016 to a cool control and two warm (air-dried interior and humid coastal) sites. We investigated survival, height, and ecophysiological traits based on three parameters: stable carbon isotope discrimination (δ13C), specific leaf area (SLA), and leaf mass specific nitrogen concentration (N) of seedlings during experiments. The survival rates of two spruce species were gradually significantly lower in warm sites, while that of Sakhalin fir did not significantly differ among sites. The relative growth rate (RGR) of two spruce species was significantly lower in the warm-interior site than in both cool control and warm-coastal sites in 2018, although in 2017 the RGR of two spruce species was lower in the warm sites than in cool control site. The less negative δ13C value in 2018 revealed that a vapor pressure deficit might decrease the spruces’ RGR via stoma closure in the warm-interior site. We found that Sakhalin fir would be less sensitive to climate change than two spruce species.

Supplementation of Enzymatic Hydrolysate in Low-Fishmeal and Low-Crop Diet Improves Growth, Antioxidant Capacity, and Immunity of Juvenile Sea Cucumber Apostichopus japonicus (Selenka)

As the global demand for aquafeed ingredients continues to rise, sourcing sustainable alternatives is crucial for aquaculture industries. This study aimed to explore the potential of enzymatic hydrolysate as a substitute for traditional fishmeal and soybean meal in diets for juvenile sea cucumbers (Apostichopus japonicus). Three isonitrogenous (15% crude protein) and isolipidic (2.4% crude lipid) diets were formulated: a control diet containing 10% fishmeal and 5% soybean meal and two experimental low-fishmeal (8%) and low-soybean meal (0%) diets, supplemented with either 8% enzymatically hydrolyzed fish stickwater (EFS) or 8% enzymatically hydrolyzed chicken pulp (ECP), designated as Control, EFS, and ECP, respectively. Juvenile sea cucumbers (initial body weight, 0.25 ± 0.01 g) were fed these diets for 84 days to evaluate the effects of ECP and EFS on their growth performance, antioxidant capacity, and inflammatory responses. The results revealed significantly higher final weights and specific growth rates in both experimental groups than the control (p < 0.05). The proximate chemical compositions of sea cucumber were less affected by the diets (p > 0.05). Compared with the control group, significantly elevated levels of digestive enzymes, antioxidants, and lysozyme, together with lower malondialdehyde levels, were recorded in the experimental groups (p < 0.05). ECP appeared to exhibit greater potency than EFS in enhancing growth performance and antioxidant capacity. Similar trends were observed in the mRNA expression of SOD, CAT, and inflammation-related genes across the groups. In a nutshell, both ECP and EFS supplemented in a low-fishmeal and low-soybean meal diet could effectively promote the growth and health of A. japonicus, with ECP showing a superior effect over EFS. These findings suggest that enzymatic hydrolysate demonstrates potential as a viable alternative to traditional fishmeal and soybean meal in diets for sustainable sea cucumber aquaculture. Further investigations are warranted to reveal its underlying mechanism.

Analysis of the efficiency of Gracilaria domingensis for an integrated multitrophic aquaculture system with Penaeus vannamei

A trial was conducted for 42 days to evaluate the zootechnical performance, water quality and phytoplankton community in an integrated multitrophic system of Penaeus vannamei with Gracilaria domingensis, using two commercial feeds. Three different densities (2.5; 5.0 and 7.5 kg m-3) with two percentages of crude protein (32% and 40%) were tested. The postlarvae were cultured for 42 days in a multitrophic biofloc system in a factorial experimental design (2x4). No significant difference for the water quality variables. For the zootechnical performance, the isolated influence of the density of G. domingensis was not observed, only the effect of the protein on the average final weight, specific growth rate, feed conversion ratio and yield, with better results in treatments with 40% crude protein. The integration with seaweed only influenced the total yield of the system, where these treatments presented higher values (from 3.68 to 8.67 kg m-3). In the phytoplankton community nine genera were identified, with Aphanocapsa being the dominant, without any significant difference among the combinations. Based on the results obtained in this study, it was found that the seaweed G. domingensis can be cultivated in a multitrophic system, without harming the water quality and the zootechnical performance.

Cost Benefits and Growth Promoting Ability of Dietary Bambara Nut (Vigna subterranean) Powder on the Rearing of Catfish (Clarias gariepinus)

The efficacy of dietary Bambara nut (Vigna subterranean) in the growth performance and cost benefit of Clarias gariepinus culture was evaluated. To this end 35% CP diet was formulated using locally available ingredients. Five different diets were prepared from the 35% CP diet, replacing Soybean with Bambara nuts at different percentage as follows: T1 (0% BN: 100 SB), T2 (25% BN: 75% SB) T3 (50% BN: 50% SB), T4 (75% BN: 25% SB) and T5 (100% BN: 0% SB), and organoleptic assessment was conducted on the diets to determine texture, aroma and color, while chemical assessment was conducted to determine the nutritional qualities of the diets. One hundred and fifty (150) sub-adult Clarias gariepinus were distributed into five (5) groups in triplicates of ten (10) using fifteen aquaria, and were fed T1 – T5, for eight (8) weeks. Length and weight of fish were evaluated fortnightly to determine: weight gain, percentage weight gain, specific growth rate, performance index and condition factor. And the cost of feed and fish were determined to evaluate the cost benefits of the various diets. At the end of the feeding trials, data were collected and analysed using ANOVA followed by a Turkey multi-companism test with SPSS 170 package software and the following results were obtained: (1) the experimental diets T1-T5 had no effects on the physico-chemical properties of the experimental waters (2) the aroma of the experimental diets were less fishy, their texture ranges from fibrous to less fibrous and the colour from dark brown to light brown as the quantity of the Bambara nut in the diets increases (T1-T5). (3) The % lipid, % proteins and % fibre decreased as the quantity of Bambara nut increased in the experimental diets (T1-T5). (4) All the growth parameters and performance index increased significantly (P<0.05) as the quantity of Bambara nuts increased in the various diets (T1-T5):- Weight gain (WG): T1 (54.61+2.11), T2 (70.96+8.47), T3 (67.82+0.63), T4 (70.90+5.90) and T5 (77.35+3.81), Percentage weight gain (PWG): T1 (30.76+0.77), T2 (40.66+1.46), T3 (35.64+1.64), T4 (37.46+1.13) and T5 (44.84+10.30); Condition factor (CF): T1 (0.55+0.13), T2 (0.62+1.02), T3 (0.70+0.41), T4 (0.64+11.4) and T5 (0.64+4.30); Specific growth rate (SGR): T1 (0.34+0.02), T2 (0.43+0.05), T3 (0.42+0.01), T4 (0.43+0.02) and T5 (0.49+0.02); Performance index (PI): T1 (158.99+2.76), T2 (208.99+25.84), T3 (210.98+2.28), T4 (203.85+11.87) and T5 (213.13+4.30). The fish fed the Bambara nut diets (T2-T5) had enhanced net profit, profit index and benefit cost ratio, but lower economic weight gain. Bambara nut is unarguably a better feed ingredient than Soybean in the culture of Clarias gariepinus.

Effect of Dietary Lactobacillus plantarum Supplementation on the Growth Performance, Intestinal Health, Antioxidant Capacity, and mTOR Signaling Pathway of Juvenile Coho Salmon (Oncorhynchus kisutch)

This study investigates the effect of dietary Lactobacillus plantarum supplementation on juvenile coho salmon (Oncorhynchus kisutch). Four groups of the juveniles (initial weight 103.87 ± 2.65 g) were fed for 10 weeks with four diets containing 0 (control diet), 105 (T1), 107 (T2), and 109 (T3) cfu/g of L. plantarum. The main results are as follows: Compared with the control diet, the final weight, specific growth rate (SGR), and weight gain rate (WGR) of the juveniles fed the T1, T2, and T3 diet significantly (p < 0.05) increased, while the feed coefficient ratio (FCR) expressed an opposite trend. The activities of superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX) in the serum of the juveniles fed the T2 diet significantly (p < 0.05) increased, while the malondialdehyde (MDA) expressed an opposite trend. The expression of phosphatidylinositol 4,5-bisphosphate 3-kinase (pi3k), AKT-interacting protein (akt), mechanistic target of rapamycin kinase (mtor), glucose-6-phosphate dehydrogenase (g6pd), sod, cat, and gsh-px genes in the liver of the juveniles fed the T2 diet significantly (p < 0.05) increased. In conclusion, the T2 diet significantly improved the growth performance, antioxidant capacity, and upregulated key mTOR pathway genes in juvenile coho salmon.

Taurochenodeoxycholic Acid Improves Growth, Physiology, Intestinal Microbiota, and Muscle Development in Red Swamp Crayfish (Procambarus clarkii)

Taurochenodeoxycholic acid (TCDCA), one of the bile acids, is thought to be involved in the regulation of muscle nutrient metabolism and gut microbial homeostasis. However, the effect of dietary addition of TCDCA on Procambarus clarkii is unclear. Therefore, in this study, an 8-week feeding experiment was conducted to explore the potential regulatory mechanisms of TCDCA on P. clarkii growth, physiology, muscle quality and gut microbes. The results indicated that dietary addition of TCDCA not only improved growth performance (final weight; weight gain; and specific growth rate) but also increased muscle elasticity and protein content. In addition, dietary TCDCA promotes muscle growth and development by increasing myofiber length, which is consistent with the activation of the expression of genes related to protein utilization (TOR and AKT) and muscle proliferation and differentiation (MyHC, MLC1, MEF2A, MEF2B). Importantly, 16s rRNA sequencing demonstrated that dietary TCDCA had no significant effect on gut microbial composition (alpha diversity) but significantly increased microbial abundance at the genus level. Functional prediction analysis of differential microbes revealed that dietary TCDCA may promote metabolism by altering gut microbes, thereby promoting muscle quality. In conclusion, our study demonstrates that the dietary addition of TCDCA promotes P. clarkii growth and muscle quality and protein deposition by altering gut microbes.

Comprehensive Multi-Scale Optimisation of Rum Fermentation

This study applied response surface methodology (RSM) to optimise process parameters for rum fermentation. The primary aim was to enhance ethanol productivity through refined molasses conditioning and fermentation. Polyacrylamide flocculants were evaluated for molasses clarification, identifying an optimised blend which significantly outperformed individual flocculants. Statistical analyses revealed Flopam AN 956 SH as the top performer based on settling behaviour and mud qualities. Mixture modelling exposed optimised flocculant formulations that outperformed individual flocculants, indicating synergistic interactions. A central composite design (CCD) systematically evaluated the effects of temperature, oxygenation, and nutrient supplementation on yeast growth kinetics. It determined that 5 ppm O2, 32.19 °C, and 2.5% nutrients maximised the specific growth rate at 0.39 h−1 and ethanol yield at 9.84% v/v. The models characterised interactions, revealing nutrient–oxygen synergies that stimulated metabolism. Overall, fermentation efficiency and assurance for ethanol yield were increased through comprehensive multi-scale optimisation utilising factorial designs, validated analytics, and quantitative strain characterisation.

Effect of Different Organic and Inorganic Fertilizers on Growth and Yield Parameters of Maize (Zea mays L.)

A field experiment was conducted during summer season of 2021-22 at Zonal Agriculture Research Station, Chhindwara, and analytical works were done in laboratories Department of Soil Science & Agricultural Chemistry, College of Agriculture, JNKVV, Jabalpur (MP). The objective of experiment was to find out the effect of different organic and inorganic fertilizers on growth parameters and yield of maize. The experiment was laid out in a randomized block design with ten treatments and three replications. The treatments were, T1 - Control (0:0:0), T2 - 100% RDF (120:60:40 kg NPK ha-1), T3 - 75% RDF, T4 - 50 % RDF, T5 - FYM 10 t ha-1 + Azotobacter, T6 - 100 % RDF + 5 t ha-1 FYM, T7 - 75 % RDF + 5 t ha-1 FYM, T8 - 50 % RDF + 5 t ha-1 FYM, T9 - 100 % RDF + 5 kg Zn ha-1 and T10 - FYM 5 t ha-1 (State practice). The result revealed that the application of Application of T6 - 100 % RDF + 5 t ha-1 FYM was recorded higher values of all the growth parameters and yield of maize at harvest viz., plant height (212.22 cm), dry matter accumulation (296.15 g/plant), leaf area index (4.335 %), crop growth rate (CGR) (24.375), relative Growth Rate (RGR) (2.711), grain yield (7844.41 kg/ha) and stover yield (14223.98 kg/ha).

Effects of dietary Lactococcus lactis Z-2 on growth, host health and resistance to Aeromonas hydrophila in juvenile common carp (Cyprinus carpio L.).

Lactococcus lactis Z-2 was previously isolated from common carp intestine. In order to investigate the effects of optimal dose of L. lactis Z-2 on growth, host health and disease resistance to Aeromonas hydrophila in common carp, five experimental diets, including without (CK and CK+ groups) or with 5 × 107 (group A), 5 × 108 (group B) and 5 × 109 CFU g-1 (group C) L. lactis Z-2, were evaluated for 8 weeks. Supplementation of L. lactis Z-2 increased final weights, weight gain, specific growth rate, condition factor and muscle crude protein content, while feed conversion ratio, muscle crude lipid and ash contents were lower than in the CK group (P < 0.05). Furthermore, L. lactis Z-2 also promoted intestinal digestive enzyme (lipase, amylase, protease) activities, improved intestinal morphology and upregulated gene (ZO-1, Occludin, Claudin) expression of intestinal barrier; stimulated secretion of proinflammatory (IL-6, IL-1β, TNF-α) and anti-inflammatory cytokines (TGF-β, IL-10) in serum; and boosted AKP, ACP, LZM and antioxidant enzyme (T-AOC, GSH-Px, T-SOD, CAT) activities of hepatopancreas (P < 0.05). Among them, the effect of group B was more prominent. After A. hydrophila infection, the CK+ group showed overexpression of immune indicators and decreased antioxidant capacity. Whereas dietary intervention with L. lactis Z-2 significantly reversed these changes. Moreover, the survival rate was significantly higher (100%) in group B than in the CK+ group (36.36%) after A. hydrophila infection (P < 0.05). Dietary L. lactis Z-2 improved the growth performance, immune response, antioxidant capacity, intestinal health and disease resistance of juvenile common carp. Ultimately, 5 × 108 CFU g-1 dietary L lactis Z-2 is recommended for the formulation of feed. © 2025 Society of Chemical Industry.

Dietary Tannic Acid Promotes Growth Performance and Resistance Against Aeromonas hydrophila Infection by Improving the Antioxidative Capacity and Intestinal Health in the Chinese Soft-Shelled Turtle (Pelodiscus sinensis).

To investigate the effect of tannic acid (TA) on the growth, disease resistance, and intestinal health of Chinese soft-shelled turtles, individual turtles were fed with 0 g/kg (CG), 0.5 g/kg, 1 g/kg, 2 g/kg, and 4 g/kg TA diets for 98 days. Afterwards, the turtles' disease resistance was tested using Aeromonas hydrophila. The results showed that 0.5-4 g/kg of dietary TA increased the growth performance and feed utilization (p < 0.05), with 2.38 g/kg being the optimal level for the specific growth rate (SGR). The addition of 0.5-4 g/kg of TA in diets increased the mucosal fold height and submucosa thickness of the small intestine, which reached a maximum of 2 g/kg. The addition of 0.5-2 g/kg of TA effectively reduced the cumulative mortality that had been induced by A. hydrophila, with the 2 g/kg dosage leading to the lowest mortality. Additionally, 1-4 g/kg of TA improved the T-SOD, CAT, and GSH-Px activities during infection, while 2 g/kg of dietary TA enhanced the richness and diversity of the microbiota, for example, by increasing Actinobacteria but inhibiting Firmicutes. The transcriptome demonstrated that the predominant differentially expressed genes (DEGs) in TA2 were mainly enriched in the PPAR signaling pathway (Acsl5, Apoa2, Apoa5, Fabp1, Fabp2, and Fabp6); in glycine, serine, and threonine metabolism (Chdh, Gatm, and Shmt1); and in steroid biosynthesis (Cel, Hsd17b7, Soat2, and Sqle). The main differentially expressed metabolites (DEMs) that were discovered by means of metabolome analysis included cholylhistidine, calcipotriol, 13-O-tetradecanoylphorbol 12-acetate, and hexahomomethionine in CG vs. TA2. Integrative analyses of two omics revealed that 2 g/kg of TA mitigated inflammation by activating the PPAR signaling pathway and regulating the lipid metabolism via multiple pathways, such as steroid biosynthesis and α-linolenic acid metabolism. In general, the inclusion of 2 g/kg of TA in turtle diets can optimally promote growth and bacterial resistance by maintaining intestinal health and improving antioxidant capacity.

Influence of Cell Physiological Status on the Intensified Fed-Batch Cultures at Ultra-High Seeding Density.

Recent years, intensified fed-batch culture with ultra-high seeding density (uHSD-IFB) is coming to the forefront of manufacturers' choice for its enhanced productivity. However, the effects of seed cell physiological state and aeration strategies on these processes remain underexplored due to the ultra-high seeding density. Currently, the pre-production seeding inoculum (N-1) crucial for the uHSD-IFB cultures relies heavily upon case-by-case empirical experiences. To develop a rational seeding approach as a guideline, we here explored the impact of perfusion rates and cell growth states on the subsequent uHSD-IFB processes. It was found that seed cells in the exponential growth phase with high perfusion rates in the N-1 perfusion stage allowed for higher viable cell density and titer in the production stage. In particular, lower levels of reactive oxygen species, higher proportions of G1 and S phase, and higher specific cell oxygen uptake rates (OURs) were exhibited in these cells, resulting in higher cell specific growth rates and integral of viable cell concentration (IVCC) throughout the production cultures. Further investigation into the effect of aeration strategies was carried out in the benchtop bioreactors. A final yield of 4.5g/L, an increase of nearly 110%, was achieved by a sophisticated dual sparger system compared to the other two processes with either one l-shaped or micro-sparger. These results provide a direction for the design and establishment of high-titer processes in intensified fed-batch cultures at ultra-high seeding density. Synopsis: In this work, we first explored the impact of perfusion rates and cell growth states on the subsequent uHSD-IFB processes. Further investigation into the effect of aeration strategies of intensified fed-batch process was carried out in the benchtop bioreactors. These results provide a direction for the design and establishment of high-titer processes in intensified fed-batch cultures at ultra-high seeding density.

A parallel bioreactor strategy to rapidly determine growth-coupling relationships for bioproduction: a mevalonate case study

BackgroundThe climate crisis and depleting fossil fuel reserves have led to a drive for ‘green’ alternatives to the way we manufacture chemicals, and the formation of a bioeconomy that reduces our reliance on petrochemical-based feedstocks. Advances in Synthetic biology have provided the opportunity to engineer micro-organisms to produce compounds from renewable feedstocks, which could play a role in replacing traditional, petrochemical based, manufacturing routes. However, there are few examples of bio-manufactured products achieving commercialisation. This may be partially due to a disparity between academic and industrial focus, and a greater emphasis needs to be placed on economic feasibility at an earlier stage. Terpenoids are a class of compounds with diverse use across fuel, materials and pharmaceutical industries and can be manufactured biologically from the key intermediate mevalonate.ResultsHere, we report on a method of utilising parallel bioreactors to rapidly map the growth-coupling relationship between the specific product formation rate, specific substrate utilisation rate and specific growth rate. Using mevalonate as an example product, a maximum product yield coefficient of 0.18 gp/gs was achieved at a growth rate (μ) of 0.34 h−1. However, this process also led to the formation of the toxic byproduct acetate, which can slow growth and cause problems during downstream processing. By using gene editing to knock out the ackA-pta operon and poxB from E. coli BW25113, we were able to achieve the same optimum production rate, without the formation of acetate.ConclusionsWe demonstrated the power of using parallel bioreactors to assess productivity and the growth-coupling relationship between growth rate and product yield coefficient of mevalonate production. Using genetic engineering, our resultant strain demonstrated rapid mevalonate formation without the unwanted byproduct acetate. Mevalonate production is quantified and reported in industrially relevant units, including key parameters like conversion efficiency that are often omitted in early-stage publications reporting only titre in g/L.

Metabolic Performance of Mealworms and Black Soldier Fly Larvae Reared on Food and Agricultural Waste and By-Products.

Mealworms and black soldier fly (BSF) larvae are two of the most reared insects at an industrial scale. Both may feed on by-products from agricultural and food industries. Feed efficiency is one of the most important aspects of such processes and varies between species and feed substrates and depends on the metabolic performance of the larvae. Compared to each other, both species may hold advantageous capabilities affecting their feed efficiency, likely depending on the feed substrate. We reared mealworms and BSF larvae on a diverse selection of by-products from agricultural and food industries, quantified major metabolic rates across their life spans, and compared their performances. The type of feed substrates had stronger effects on the growth of mealworms than on black soldier fly larvae. Generally, BSF larvae were advantageous in terms of the highest maximal specific growth rate (0.50-0.77 day-1) and feed assimilation rate (0.81-1.16 day-1) and shortest development period (23-25 days) but disadvantageous in terms of metabolic maintenance cost (0.07-0.21 day-1). In mealworms, the maximal specific growth rates were 0.02-0.11 day-1, the highest feed assimilation rates were 0.16-0.37 day-1, and the development period was at least 65-93 days, while maintenance was only 0.02-0.05 day-1. In contrast to the BSF larvae, the specific maintenance rate was weight dependent in the mealworms and lowest in the largest individuals. The combined outcome of these metabolic rates resulted in an average carbon net growth efficiency, NGE*avg of 0.16-0.40 in mealworms and 0.33-0.56 in BSF larvae across their life span. It thus seems that BSF larvae are more versatile and somewhat more efficient at converting diverse feed substrates into growth than mealworms. Differences in NGE*avg affected the substrate conversion efficiencies (i.e., the ratio of the weight gain of the larvae to the reduced weight of feed substrates) and may thus impact the overall outcome of insect farming.

Replacement of fishmeal with Quinoa Husk (Chenopodium quinoa) for mitigating multiple stresses in Pangasianodon Hypophthalmus

The fishmeal is boon for aquaculture production in this recent pollution and climate change era. However, the demand of fishmeal is enhancing in many folds which needs to find alternative to fishmeal in cheap price. The present investigation addresses these issues with quinoa husk (QH). An experiment was performed to evaluate replacement of fishmeal by QH in different proportionate at 0, 15, 20, 25, 30 and 35%. The study was designed with 12 treatments as control, stressors group (concurrent exposed to ammonia, arsenic and high temperature stress, NH3+As+T), group fed with QH at 15, 20, 25, 30 and 35% without and with stressors (NH3+As+T) in Pangasianodon hypophthalmus for 105 days. The optimization of QH dose for growth performance such as food conversion ratio, growth rate, protein efficiency ratio and specific growth rate with respect to protein percentage and obtained 26%. The oxidative enzymes such as superoxide dismutase (SOD), catalase (CAT), glutathione-s-transferase (GST) and glutathione peroxidase (GPx) in gill, kidney and liver tissues were significantly lowered by replacement of fishmeal by QH at 25% in fish reared under arsenic and ammonia toxicity and high temperature stress (NH3+As+T). The neurotransmitter enzyme (AChE) in brain tissue was noticeably enhanced by QH at 25%. The aspartate amino transferase (AST) and alanine amino transferase (ALT) as well as malate dehydrogenase (MDH) and lactate dehydrogenase (LDH) in gill and liver were significantly reduced by QH at 25% in fish reread under multiple stresses (NH3+As+T). The nitro blue tetrazolium (NBT), blood glucose, albumin, globulin, total protein, A:G ratio, myeloperoxidase (MPO) and total immunoglobulin (Ig) were noticeably improved by supplementation of QH at 25–30% in fish reared under NH3+As+T. The amylase, protease and lipase were significant improved with replacement of fishmeal by QH at 25%. The histo-pathological alterations were marked in liver and gill tissues, whereas these tissues were protected by QH at 25% in fish reared under control and stress condition (NH3+As+T). The present study revealed that replacement of fishmeal at 25% by QH could be a better replacement for improvement in anti-oxidative status, acetylcholine esterase and growth performance in fish reread under NH3+As+T stress.