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Accurate and reliable estimation of specific growth rate (μ) in real-time is pivotal for reliable process monitoring of a bioprocess and subsequent implementation of advanced control strategies. Gibbs free energy dissipation is imminent for any biological system, and the metabolic heat flow measurements (calorimetry) formed the basis for estimating μ. However, the rationale behind selecting a suitable μ estimator model based on calorimetric perspective remains unexplored. The present investigation addresses the notion behind the selection of an appropriate estimator for μ and the assessment of the estimator models was illustrated using different types of energy metabolism, namely, high exothermic and low exothermic processes. The results indicated that the μ values from the instantaneous heat flow estimator significantly deviated (10-fold higher) from the offline values for highly exothermic process. Notably, the cumulative heat-based estimator accurately estimated μ values on both types of energy metabolism with performance metrics <0.005 h−1. [Display omitted] [ABSTRACT FROM AUTHOR]

This study investigated the influence of visual and chemical stimuli from live prey on juvenile Florida pompano (Trachinotus carolinus) growth. Twelve tanks within four independent recirculating systems housed fish of similar weight (obtained from a commercial fish farm) in groups of ten. Prior to their morning feeding (they were fed twice daily at 10 h and 16 h with commercial pellets), fish were exposed to one of four stimuli: visual and chemical cues from Artemia, mole crab, feed pellets (control for stimuli), or seawater (control for procedures). Key growth parameters were monitored weekly for seven weeks, including feed intake, weight gain, and specific growth rate (SGR). Fish exposed to Artemia and mole crab stimuli exhibited significantly higher feed intake (23.11 ± 1.37 and 23.45 ± 1.38 g/fish), weight gain (169.28 ± 7.59 and 172.75 ± 12.57%), and SGR (2.02 ± 0.05 and 2.04 ± 0.09% day−1) compared to those exposed to feed pellets (stimuli control) and seawater (procedures control): feed intake (20.81 ± 0.684 and 19.30 ± 0.39 g/fish), weight gain (136.25 ± 4.51 and 140.23 ± 6.36%), and SGR (1.75 ± 0.03 and 1.78 ± 0.05%.day−1). These findings highlight the importance of visual and chemical cues from live prey as feeding incitants and stimulants. By enhancing feeding motivation and intake, these stimuli promote growth and potentially improve the welfare of juvenile Florida pompano. [ABSTRACT FROM AUTHOR]

Abstract The objective of this study was to develop a nomogram model based on the natural progression of tumor and other radiological features to discriminate between solitary nodular pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinomas. A retrospective analysis was conducted on 15,655 cases of lung adenocarcinoma diagnosed at our institution between January 2010 and June 2023. Primary nodular invasive mucinous adenocarcinomas and non-mucinous adenocarcinomas with at least two preoperative CT scans were included. These patients were randomly assigned to training and validation sets. Univariate and multivariate analyses were employed to compare tumor growth rates and clinical radiological characteristics between the two groups in the training set. A nomogram model was constructed based on the results of multivariate analysis. The diagnostic value of the model was evaluated in both the training and validation sets using calibration curves and receiver operating characteristic curves (ROC). The study included 174 patients, with 58 cases of mucinous adenocarcinoma and 116 cases of non-mucinous adenocarcinoma. The nomogram model incorporated the maximum tumor diameter, the consolidation/tumor ratio (CTR), and the specific growth rate (SGR) to generate individual scores for each patient, which were then accumulated to obtain a total score indicative of the likelihood of developing mucinous or non-mucinous adenocarcinoma. The model demonstrated excellent discriminative ability with an area under the receiver operating characteristic curve of 0.784 for the training set and 0.833 for the testing set. The nomogram model developed in this study, integrating SGR with other radiological and clinical parameters, provides a valuable and accurate tool for differentiating between solitary nodular pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinomas. This prognostic model offers a robust and objective basis for personalized management of patients with pulmonary adenocarcinomas.

Background Nile tilapia ( Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent “ b” values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control ( b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

The objective of this study was to develop a nomogram model based on the natural progression of tumor and other radiological features to discriminate between solitary nodular pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinomas. A retrospective analysis was conducted on 15,655 cases of lung adenocarcinoma diagnosed at our institution between January 2010 and June 2023. Primary nodular invasive mucinous adenocarcinomas and non-mucinous adenocarcinomas with at least two preoperative CT scans were included. These patients were randomly assigned to training and validation sets. Univariate and multivariate analyses were employed to compare tumor growth rates and clinical radiological characteristics between the two groups in the training set. A nomogram model was constructed based on the results of multivariate analysis. The diagnostic value of the model was evaluated in both the training and validation sets using calibration curves and receiver operating characteristic curves (ROC). The study included 174 patients, with 58 cases of mucinous adenocarcinoma and 116 cases of non-mucinous adenocarcinoma. The nomogram model incorporated the maximum tumor diameter, the consolidation/tumor ratio (CTR), and the specific growth rate (SGR) to generate individual scores for each patient, which were then accumulated to obtain a total score indicative of the likelihood of developing mucinous or non-mucinous adenocarcinoma. The model demonstrated excellent discriminative ability with an area under the receiver operating characteristic curve of 0.784 for the training set and 0.833 for the testing set. The nomogram model developed in this study, integrating SGR with other radiological and clinical parameters, provides a valuable and accurate tool for differentiating between solitary nodular pulmonary mucinous adenocarcinoma and non-mucinous adenocarcinomas. This prognostic model offers a robust and objective basis for personalized management of patients with pulmonary adenocarcinomas. [ABSTRACT FROM AUTHOR]

The effect of glyphosate herbicide at concentrations of 25, 100, 150 and 200 μg.L−1 on growth characteristics of diatoms C. caspia and T. weissflogii under accumulative growth conditions was investigated. Increasing herbicide concentration in the medium resulted in growth suppression of both species and decreased the final abundance of the cultures in the stationary growth phase. The calculated concentrations of herbicide EC10 and EC50 (10 and 90 μg.L−1 for C. caspia and 7 and 25 μg·L−1 for T. weissflogii, respectively) led to a 10 and 50% reduction in the abundance of the studied cultures relative to the control, are ecologically significant and correspond to the values recorded in aquatic areas. The combined effect of light (in the range of 20–250 µE.m−2.s−1) and glyphosate (calculated concentrations of EC10 and EC50) on the growth characteristics of microalgae was evaluated. An increase in algal sensitivity to light was observed with glyphosate exposure. In both species, the increase in the concentration of glyphosate in the medium led to a decrease in the initial angle of slope of the light curve of growth under conditions of light limitation, a reduction in the value of light saturation of growth, narrowing of the boundaries of the light optimum and an increase in the degree of light inhibition. It is shown that the effect of the combined action of light and glyphosate exceeds the sum of the effects of each factor. This fact should be taken into account in ecotoxicological monitoring when assessing the risks of glyphosate ingress into aquatic ecosystems. An increase in glyphosate concentration in water during periods with high values of solar insolation is potentially dangerous due to a decrease in the photosynthetic activity of algae and a reduction in diatom algae abundance. [ABSTRACT FROM AUTHOR]

This study investigates ultrasonic energy’s impact on enhancing the growth of Botryococcus braunii (B. braunii) microalgae. Microalgae, known for their advantages in greenhouse gas mitigation and biomass conversion, were subjected to various stressors, including ultrasonic waves, to optimize productivity. Ultrasonic waves induce acoustic cavitation, increasing membrane permeability and substrate conversion. The study examined the impact of energy and maximum pressure resulting from bubble collapse on the relative specific growth rate of B. braunii microalgae. It was observed that reproduction showed a promotive trend until the energy surpassed 30 kJ. However, when ultrasonic energy reached 18.2 kJ, reproduction was inhibited due to the maximum pressure generated during bubble bursting, which reached 5.7 µN/µm², leading to the suppression of reproduction upon encountering bubble collapse events. Under specific ultrasonic conditions (15.1 kJ energy, maximum pressure of 45.5 × 105 Pa), a maximum specific growth rate of 0.329 ± 0.020 day−1 in a two-day interval boosted B. braunii microalgae biomass productivity. These findings advance our understanding of ultrasonic wave effects on microalgae reproduction and underscore the potential for optimizing ultrasonic parameters to enhance biomass production. [ABSTRACT FROM AUTHOR]

This comprehensive study explores the intricate relationships between nutrient conditions and the growth patterns of Thalassiosira weissflogii and Chaetoceros calcitrans. Distinct flasks, subjected to varied nutrient compositions, were monitored for cell density and specific growth rates over a span of 168 hours. T. weissflogii exhibited distinct responses to F/2 Guillard media, with notable changes in cell density and growth rates, while C. calcitrans showcased nuanced dynamics under different nutrient conditions. The molecular confirmation, ITS gene sequence were done for the two microalgae strains that were bound to marine. High percentage similarity in the BLAST results of the microalgae sequences identified the species as Thalassiosira weissflogii (99.84%) and Chaetoceros calcitrans (99.79%). To accurately identify microalgae at the genus and species levels, a combination of the classical and genetic approaches is essential. The findings offer valuable insights into optimizing microalgae cultivation for biotechnological and environmental applications. [ABSTRACT FROM AUTHOR]

This research investigates the growth performance of Clarias batrachus when supplemented with Pleurotus florida freeze-dried extract (PFME) over 60 days. Triplicate groups of fish were fed experimental diets containing varying concentrations of PFME (0.5%, 1%, 1.5% and 2%), each adjusted to 5% of their wet body weight biweekly. Results demonstrate that PFME-enriched diets significantly enhanced the growth metrics of Clarias batrachus compared to a control group fed a standard diet. Fish fed with Diet III, containing 1.5% PFME, exhibited the highest weight gain of 31.98 ± 0.45 grams, followed by Diet IV (26.59 ± 0.33 grams), Diet II (25.26 ± 0.49 grams), Diet I (23.90 ± 0.30 grams), and the control group (17.78 ± 0.61 grams). This trend in weight gain correlates with biweekly measurements showing accelerated growth, particularly evident after the first month of feeding. Length measurements also reflected enhanced growth rates, with Diet III yielding the longest fish at 21.24 ± 0.38 cm. Furthermore, specific growth rates were notably higher in fish-fed Diet III (2.11 ± 0.05%), indicating superior growth potential compared to other diets and the control. Feed conversion ratios (FCR) were comparable across experimental diets, suggesting efficient feed utilization, particularly evident in Diet III (FCR 1.55 ± 0.45), which required less feed to produce more fish biomass. Moreover, PFME supplementation positively influenced the feeding rates and survival rates of Clarias batrachus. Fish on Diet III exhibited a consistent feeding rate (3.01 ± 0.06%) similar to other experimental diets, while achieving a high survival rate of 100 ± 0.02%, signifying improved health and immunity. Pleurotus florida extract, particularly at 1.5% concentration (Diet III), proves effective in enhancing the growth performance of Clarias batrachus. This study underscores PFME's potential as a beneficial dietary supplement in the aquaculture, promoting efficient growth and potentially reducing production costs. Further research into the physiological mechanisms underlying these effects could provide deeper insights into optimizing fish nutrition and health in aquaculture settings. [ABSTRACT FROM AUTHOR]

Microalgal density is one of the factors affecting bioremediation efficiency, but literature on the density that efficiently removes nitrogen and phosphorus from aquaculture wastewater is still very limited. Thus, this study was conducted to optimize the density of Isochrysis galbana, Nannochlorum sp., and Tetraselmis tetrahele to efficiently remove inorganic N (NH3-N, NO2-N) and P. Three densities such as low, medium, and high with an optical density at 680 nm of 0.1, 0.2, and 0.3, respectively, were evaluated for 12 days. Results showed that medium density was good for Isochrysis galbana and Nannochlorum sp. in the removal of both N and P with rates reaching 97.93% and 84.07%, 94.25% and 93.39%, and 59.39% and 71.65% for NH3-N, NO2-N, and P, respectively. For Tetraselmis tetrahele, the low density efficiently removed N, while the high density effectively removed P with the highest removal of 99.16%, 97.5%, and 51.55% for NH3-N, NO2-N, and P, respectively. Specific growth rates of Isochrysis galbana and Tetraselmis tetrahele were affected by density; the lower the densities, the higher their growth rates. The three densities did not differ significantly in Nannochlorum sp. Isochrysis galbana and Nannochlorum sp. biomass productivity were high in medium and high densities, while low and medium densities for Tetraselmis tetrahele. Overall, the optimization of microalgal density is beneficial in the efficient removal of nitrogen and phosphorus from aquaculture wastewater. [ABSTRACT FROM AUTHOR]

During the epoch of sustainable development, leveraging cellular systems for production of diverse chemicals via fermentation has garnered attention. Industrial fermentation, extending beyond strain efficiency and optimal conditions, necessitates a profound understanding of microorganism growth characteristics. Specific growth rate (SGR) is designated as a key variable due to its influence on cellular physiology, product synthesis rates and end-product quality. Despite its significance, the lack of real-time measurements and robust control systems hampers SGR control strategy implementation. The narrative in this contribution delves into the challenges associated with the SGR control and presents perspectives on various control strategies, integration of soft-sensors for real-time measurement and control of SGR. The discussion highlights practical and simple SGR control schemes, suggesting their seamless integration into industrial fermenters. Recommendations provided aim to propose new algorithms accommodating mechanistic and data-driven modelling for enhanced progress in industrial fermentation in the context of sustainable bioprocessing. [ABSTRACT FROM AUTHOR]

The joint dynamics of phytoplankton parameters (primary production, specific growth rate, and biomass) and amount of precipitation in coastal regions and on the shelf in the northern part of the Black Sea in 1998–2015 are studied based on satellite data (SG) (GPCPMON) GPCP Version 3.2, TRMM TMPA (3B42RT), SeaWiFS from 1998 to 2010, MODIS-Aqua from 2002 to 2015, and MODIS-Terra from 2000 to 2015. The phytoplankton parameters are calculated according to earlier developed models. Their monthly average values, as well as bi-weekly and daily values of atmospheric precipitation are assessed. As a result of the study, insignificance of the part of atmospheric precipitation in the variability of phytoplankton parameters on vast water areas and long time periods is revealed. It sometimes increases to 30% in offshore areas in the presence of influxes of large rivers. The effect of atmospheric precipitation on the biological productivity of phytoplankton in small bounded water areas and short time periods is more pronounced. According to our data for 18 years, a correlation between the specific growth rate and precipitation on the Black Sea shelf is stronger in winter than in other seasons; the correlations of biomass and primary production of phytoplankton with atmospheric precipitation are less pronounced. The specific growth rate of phytoplankton correlates with precipitation stronger than other phytoplankton parameters under study. An increase in the amount of precipitation over previous level with the monthly averages above 0.6 mm/day increases the specific growth rate or maintained it at the same level. The increase in the specific growth rate is not the same everywhere and not proportional to the amount of atmospheric precipitation. This witnesses the influence of many factors on the phytoplankton parameters; however, precipitation could be an additional stimulating factor. [ABSTRACT FROM AUTHOR]

Despite the importance of juvenile growth to lifetime fitness, high variability exists within many fish species where some individuals grow markedly faster than others. Here, we explored whether social context mediated growth performance in n = 35 Galaxias maculatus by manipulating the social environment after identifying different growth phenotypes. We found that initially fast-growing fish slowed their growth rate when pooled with similarly fast-growing individuals, whereas none of the initially slow-growing fish markedly improved their growth when pooled with other slow-growers. We examined for any metabolic underpinnings to the findings by measuring standard, routine, and maximum metabolic rates (SMR, RMR, and MMR) at two time points separated by ~4 months. SMR and RMR positively correlated with growth rates when the fish were pooled into growth phenotypes, but not when they were returned to their original (mixed) social groups. We highlight research directions to further elucidate how social context and metabolism interact to govern growth phenotype.

Background Nile tilapia (Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent “b” values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control (b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

The effects of growth and reproduction on the marine Cyclops sp. were investigated using three microalgae as diets. The development period of Cyclops sp. was evaluated at 106 cells/ml in 15ppt salinity to identify the stationary phase. The survival rate of marine Cyclops from nauplius to adult differed according to the microalgal diet. The results showed that the shortest time (14 days) and highest survival (17.6 ± 0.131 %) for Cyclops sp. was achieved with those fed with Nannochloropsis sp. Whereas, it took longest time (37 days) and lowest survival rate (6.40 ± 0.035 %) when fed Chlamydomonas sp. The developmental period from naupli (I - VI) (6.91 ± 0.453 days), copepodite (I - VI) (11.4 ± 0.311days) and naupli to adult (20 ± 1.08 days) appeared significantly longer when fed with Nannochloropsis sp. compared to other treatments. The daily mean naupli production of adult females over 7 days was significantly higher (p ˂ 0.05) in Nannochloropsis sp. compared with Chlamydomonas sp. and Gonyostomum sp. On the 25th day of Nannochloropsis sp. treatment, 99 % of the mature females died. Production (naupli, copepodite adult male and adult female) was significantly higher (p ˂ 0.05) in Nannochloropsis sp. than in other microalgal diets. On the fifteenth day, Nannochloropsis sp. showed a significantly higher (p ˂ 0.05) specific growth rate than other microalgal diets. Nannochloropsis sp. had the highest nauplius survival rate on the sixth day compared to other microalgal diets. With Nannochloropsis sp., the species has a higher hatching rate, and in Chlamydomonas sp. hatching occurs earlier. The average lifespan for Nannochloropsis sp. was 46 days, for Chlamydomonas sp. it was 37 days, and for Gonyostomum sp. it was 32 days.

Data variability complicates reproducibility and the interpretation of experimental results. Different animal models have been employed to decrease variability to enhance experimental power. However, variation frequently persists among and within strains/lines. In zebrafish (Danio rerio), inbred lines (e.g., NHGRI-1) derived from wild-type lines have been produced to greatly decrease genetic variation, with the goal of providing better understanding of genetic backgrounds that may influence the experimental outcome of studies employing such lines. We hypothesized that variations in morphological phenotypes shaped by environmental stressors early in development are correlated with the intrinsic degree of genetic variability of zebrafish lines. We compared morphological variability (yolk–chorion ratio, body mass, embryo mass, total length, condition factor, and specific growth rate) in wild-type AB and NHGRI-1 zebrafish lines as a function of their responses to altered temperature and oxygen availability during the first 7 days post-fertilization. Overall, both lines showed similar developmental trajectories for yolk–chorion ratio, embryo mass, and total length. Additionally, condition factor and specific growth rate showed similar responses within each line, regardless of temperature and hypoxia. Importantly, the coefficient of variation for each variable was significantly lower in NHGRI-1 than AB larvae for 151 of 187 assessed morphological endpoints. Thus, the low-heterozygosity NHGRI-1 zebrafish line can be useful for decreasing inter-individual variation in morphological responses to environmental stressors, thereby aiding in the interpretation of results and enhancing experimental reproducibility. [ABSTRACT FROM AUTHOR]

Simple Summary: The study focused on cultivating the cyanobacterial strain Nostoc sp. 136 under controlled laboratory conditions. Various factors such as nutrient media, initial biomass concentration, nutrient supplementation, and light conditions were investigated to optimize growth and productivity. Results showed that the strain adapted well to the laboratory conditions, with the highest growth rates observed at lower initial biomass concentrations and with mBG11 medium. Nutrient supplementation, particularly nitrogen, showed potential for enhancing growth, while different light wavelengths had varied effects on growth and productivity. Biochemical analysis revealed promising levels of proteins and phycobiliproteins, with potential applications in biotechnology. The study highlighted the suitability of Nostoc sp. 136 for laboratory cultivation and suggested avenues for further research, particularly in exploring biomass composition and bioactivities. Cyanobacteria, photoautotrophic Gram-negative bacteria, play a crucial role in aquatic and terrestrial environments, contributing significantly to fundamental ecological processes and displaying potential for various biotechnological applications. It is, therefore, critical to identify viable strains for aquaculture and establish accurate culture parameters to ensure an extensive biomass supply for biotechnology purposes. This study aims to establish optimal laboratory batch culture conditions for Nostoc 136, sourced from Alga2O, Coimbra, Portugal. Preliminary investigations were conducted to identify the optimal culture parameters and to perform biomass analysis, including protein and pigment content. The highest growth was achieved with an initial inoculum concentration of 1 g.L−1, using modified BG11 supplemented with nitrogen, resulting in a Specific Growth Rate (SGR) of 0.232 ± 0.017 μ.day−1. When exposed to white, red, and blue LED light, the most favourable growth occurred under a combination of white and red LED light exhibiting an SGR of 0.142 ± 0.020 μ.day−1. The protein content was determined to be 10.80 ± 2.09%. Regarding the pigments, phycocyanin reached a concentration of 200.29 ± 30.07 µg.mL−1, phycoerythrin 148.29 ± 26.74 µg.mL−1, and allophycocyanin 10.69 ± 6.07 µg.mL−1. This study underscores the influence of light and nutrient supplementation on the growth of the Nostoc biomass. [ABSTRACT FROM AUTHOR]

Polyculture of amur common carp with catla and rohu was compared with common carp, catla and rohu polyculture in the earthen ponds of Mysuru district in Karnataka. Stocking density of 1 no./mt2 was used in two treatment sets with periodical water quality monitoring. Six essential water quality parameters were monitored throughout the study period and with scientific management practices, the water parameters remained in optimal limits supporting the fish growth. Amur common carp with catla and rohu yielded the better yield and survival rate compared to the common carp poly culture. The SGR (Specific Growth Rate) was also high followed by common carp and catla. The mean weight of the Amur common carp was found to be 1506 gm in T1 whereas, common carp was 1286 gm in T2. The Amur Common Carp also exhibited highest survival rate out of all the species in both the treatments with 84.88%. The yield data also reviled that Amur common carp polyculture is 10.53% more compared to the common carp polyculture. [ABSTRACT FROM AUTHOR]

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Exercise training may be an effective tool for promoting growth and production efficiency in finfish aquaculture. Yet, changes in growth and feed conversion ratios (FCR) following periods of exercise can be varied and context dependent. Variation in species and training protocols (duration, intensity and regime) can misalign interpretations, and individual studies hold limited statistical power. To remedy this, we compiled data from 69 studies spanning 31 species to quantify the effects of exercise training on growth rates and FCRs. Using meta‐analytic tools, we show that exercise training significantly increases growth rates across a range of taxonomically diverse finfish. Optimal training regimes were identified; effects were strongest when fish were exercised continuously rather than intermittently, at target swimming speeds ≤ 2 body lengths s−1, for longer durations of time. These results are most applicable to juvenile fish (mean length of fish in the analyses = 16 cm). Exercise training was also shown to decrease variability in growth rates, leading to fish that are more uniform in size. FCRs were unaffected by exercise, showing that exercised‐ and control‐fish were equally efficient at converting food into body mass. Overall, our analyses show that exercise is a powerful management tool in promoting rapid growth, where fish can reach marketable sizes faster. [ABSTRACT FROM AUTHOR]

A 90-day feeding trial was conducted to investigate the effects of phytase supplemented Distiller’s Dried Grains with Soluble (DDGS) based diet on the production performance, tissue composition, nutrient digestibility and activity of anti-oxidant enzymes in the gills of mrigal (Cirrhinus mrigala) juveniles. Six experimental diets were formulated to contain increasing levels of supplemental phytase, 0 (D1), 250 (D2), 500 (D3), 750 (D4), 1000 (D5), and 1250 (D6) phytase (FTU/kg). Each experimental diet was randomly assigned and fed three times daily to triplicate groups of 180 fish. Significant increase in body weight gain and specific growth rate, feed conversion and protein efficiency ratios of groups fed up to 750 FTU/kg were observed. Broken line analysis of Specific Growth Rate showed that the optimal dietary phytase level of mrigal juveniles is 750 FTU /kg or higher than this dose. Results among protein, lipid, moisture, ash and P contents of whole body, muscle, liver and viscera were not significantly different as phytase level increased from 250 FTU/kg to 1250 FTU/kg (D2 to D6). It was concluded that phytase at the rate of 750 FTU /kg is the optimum dose for the enhanced growth in juvenile mrigal.

Background Nile tilapia ( Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent ' b' values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control ( b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

The main aim of this work is to study the effect of different nutrient supply systems and their effect on the performance of the Nile Tilapia (Oreochromis niloticus) and Lettuce (Lactuca sativa var. crispa) plant integration system. To achieve that, five treatments having different culture systems (T1: Aquaculture (control), T2: Hydroponics (standard requirement: N = 210, P = 31, K = 234, Mg = 48, Ca = 200, S = 64, Fe = 14, Mn = 0.5, Zn = 0.05, B = 0.5, Cu = 0.02 and Mo = 0.01 ppm), T3: Aquaponics without nutrients addition, T4: Aquaponics with supplementary nutrients (KNO3, 101 g L−1, KH2PO4, 136 g L−1, Ca(NO3)2, 236 g L−1, MgSO4, 246 g L−1, K2SO4, 115 g L−1 and chelates for trace elements) in water (EC is 800 ppm) and T5: Aquaponics with supplementary nutrients spray on plants) were carried out. The previous systems were operated at three flow rates, namely, 1.0, 1.5 and 2.0 L h−1 plant−1. The various water quality parameters, plant growth and fish growth were studied. The result indicated that the highest values of N, P, k, Ca and Mg consumption rate were found with T2 and 1.5 L h−1 plant−1 of flow rate. The root length, fresh and dry of shoot and root for lettuce plants grown in T2 system was better than those grown in different culture system (T3, T4 and T5). Different culture systems showed significant effect on fish growth in terms of weight gain, specific growth rate and feed efficiency ratio. Higher growth rate was observed in treatment T3 as compared to other treatments. The production costs ranged from 2820.5 to 4885.4 LE ($ = 30.92 LE) for all culture systems. [ABSTRACT FROM AUTHOR]

The growth of cultured juvenile fish is usually quantified by two indexes, the specific growth rate or SGR, and the thermal-unit growth coefficient or TGC. The SGR is a relative growth index based on logarithms of body weights, and it decreases with body weight. The classical TGC is based on one-third powers of body weights and the summation of temperature over time. It can also depend on bodyweight, but it is possible to release this dependency by empirically adjusting the power function in its mathematical definition. These two indexes are usually presented in the same article to compare the growth attained by different groups of fish subjected to different experimental treatments. However, no formal framework linking both indexes is available for researchers up to the moment, the meanings of SGR and TGC remaining unrelated. The present work shows that the TGC of a group of fish growing at a given temperature can be expressed as a function of the SGR. In addition, the relationship between SGR and TGC here reported provides the basis to re-defined the TGC as a size-independent index with application to fish culture. [ABSTRACT FROM AUTHOR]

Solid tumors frequently present a heterogeneous tumor microenvironment. Because tumors have the potential to proliferate quickly, the consequence is a reduction in the nutrients, a reduction in the pH (<6.8), and a hypoxic environment. Although it is often assumed that tumor clones show a similar growth rate with little variations in nutrient consumption, the present study shows how growth-specific rate (µ), the specific rates of glucose, lactate, and glutamine consumption (qS), and the specific rates of lactate and glutamate production (qP) of 2D-cultured lung tumor cells are affected by changes in their environment. We determined in lung tumor cells (A427, A549, Calu-1, and SKMES-1) the above mentioned kinetic parameters during the exponential phase under different culture conditions, varying the predominant carbon source, pH, and oxygen tension. MCF-7 cells, a breast tumor cell line that can consume lactate, and non-transformed fibroblast cells (MRC-5) were included as controls. We also analyzed how cell-cycle progression and the amino acid transporter CD98 expression were affected. Our results show that: (1) In glucose presence, μ increased, but qS Glucose and qP Lactate decreased when tumor cells were cultured under acidosis as opposed to neutral conditions; (2) most lung cancer cell lines consumed lactate under normoxia or hypoxia; (3) although qS Glutamine diminished under hypoxia or acidosis, it slightly increased in lactate presence, a finding that was associated with CD98 upregulation; and (4) under acidosis, G0/G1 arrest was induced in A427 cancer cells, although this phenomenon was significantly increased when glucose was changed by lactate as the predominant carbon-source. Hence, our results provide an understanding of metabolic responses that tumor cells develop to survive under stressful conditions, providing clues for developing promising opportunities to improve traditional cancer therapies. [ABSTRACT FROM AUTHOR]

The study on the bioleaching of metals from minerals is a necessity to improve the process of recovering precious metals and obtaining greater benefits. The objective was to determine in four successive reactivations, the specific growth rate and stability of microbial consortia obtained from the leaching plant of the mining company Southern Cooper Corporation (SCC) in Toquepala, Tacna - Peru. The consortia M-1, M-2, M-5, M-6, and BF-7 were obtained from chalcopyrite from the leach heaps; and the PLS-3, PLS-4, and ILS-8 of the leached liquid solutions. The liquid culture medium used was modified to 9K. The consortia had four successive reactivations in 9K medium, in triplicate, at room temperature for 15 days and with 1vvm aeration. The microbial counts obtained every eight hours in the Petroff-Hausser counting chamber were converted to the decimal logarithmic scale to obtain the growth kinetics using the Malthusian model that determined the rate constant K in the logarithmic phase and the Gompertz model to the microbial growth curve. The consortia from solid samples and biofilm had a faster adaptation, compared to those from the liquid samples of PLS and ILS, which showed an inactive microbial concentration at the beginning. All consortia after the first reactivation showed higher growth rates, the highest being in the PLS-4 consortium during the third reactivation, with a K of 0.025 h-1. The most stable growth rates occurred in the fourth reactivation in the M-6 and BF-7 consortia, these were the most indicated to continue with application studies as inoculum after a third reactivation and achieve the optimization of the bioleaching process of the mineral chalcopyrite. [ABSTRACT FROM AUTHOR]

Microalgae have emerged as a promising alternative biomass source, offering distinct advantages over conventional crops in terms of oil content per mass. Maximizing their reproductive capacity throughout their life cycle is essential for optimizing biomass production. This study investigates the influence of ultrasonic waves on the reproductive rate of Botryococcus braunii microalgae. Various ultrasonic parameters, including power (56.2, 86.3, and 132.2 W for 37 kHz; 46.3, 67.2, and 101.2 W for 80 kHz), exposure times (3 and 5 min), and time intervals (2 and 4 days) were examined. The best outcomes were obtained with a 37 kHz ultrasonic frequency, 83.6 W power, 3-min exposure, and a 2-day interval, resulting in a maximum relative specific growth rate (16.67%) and relative biomass productivity (34.62%). Beyond these parameters, adjustments in ultrasonic treatment conditions resulted in decreased growth rates and biomass productivity. It is crucial to consider multiple ultrasonic factors, including frequency, power, exposure time, and time intervals, as each parameter significantly impacts microalgae growth. [ABSTRACT FROM AUTHOR]

A 90-day feeding trial was conducted to investigate the effects of phytase supplemented Distiller's Dried Grains with Soluble (DDGS) based diet on the production performance, tissue composition, nutrient digestibility and activity of anti-oxidant enzymes in the gills of mrigal (Cirrhinus mrigala) juveniles. Six experimental diets were formulated to contain increasing levels of supplemental phytase, 0 (D1), 250 (D2), 500 (D3), 750 (D4), 1000 (D5), and 1250 (D6) phytase (FTU/kg). Each experimental diet was randomly assigned and fed three times daily to triplicate groups of 180 fish. Significant increase in body weight gain and specific growth rate, feed conversion and protein efficiency ratios of groups fed up to 750 FTU/kg were observed. Broken line analysis of Specific Growth Rate showed that the optimal dietary phytase level of mrigal juveniles is 750 FTU /kg or higher than this dose. Results among protein, lipid, moisture, ash and P contents of whole body, muscle, liver and viscera were not significantly different as phytase level increased from 250 FTU/kg to 1250 FTU/kg (D2 to D6). It was concluded that phytase at the rate of 750 FTU /kg is the optimum dose for the enhanced growth in juvenile mrigal. [ABSTRACT FROM AUTHOR]

Vibrio natriegens is a halophilic bacterium with the fastest generation time of non-pathogenic bacteria reported so far. It therefore has high potential as a production strain for biotechnological production processes or other applications in biotechnology. Culture media for V. natriegens typically contain high sodium chloride concentrations. The corresponding high chloride concentrations can lead to corrosion processes on metal surfaces in bioreactors. Here we report the development of a low-chloride chemically defined medium for V. natriegens. Sodium chloride was completely replaced by the sodium salts disodium hydrogen phosphate, disodium sulfate, and sodium citrate, while keeping the total concentration of sodium ions constant. The use of citrate prevents the occurrence of precipitates, especially of ammonium magnesium phosphate. With this defined medium, high-cell-density fed-batch cultivations in laboratory-scale bioreactors using exponential feeding yielded biomass concentrations of more than 60 g L−1. Key points: A defined medium for V. natriegens that only contains traces of chloride was developed Corrosion processes on metal surfaces in industrial bioreactors can thus be prevented High yields of biomass can be achieved in fed-batch cultivation with this medium [ABSTRACT FROM AUTHOR]

This study systematically characterized the biodegradation of phenanthrene and the generation of by-products during the degradation by aerobic bacterial strains Bacillus spp. inhabited the phyllosphere of ornamental plants grown in urban polluted areas. The HPLC results revealed that four isolated Bacillus spp. (Bacillus sp.1—95%, Bacillus velezensis—90%, Bacillus megaterium—91%, Bacillus sp. P2B-02—93%) were able to degrade more than 88% of phenanthrene within the first 2 days of incubation with the specific growth rate of 0.0773 day−1, 0.0993 day−1, 0.0993 day−1, and 0.302 day−1, respectively. The results of the kinetic assay revealed that the isolated four bacterial strains followed the first-order kinetics, and out of them, Bacillus sp. P2B-02 had the shortest half-life (2.82 ± 0.07 days) and the highest specific growth rate of phenanthrene degradation (0.302 day−1). In addition to the phenanthrene peak, all four bacterial strains showed an additional peak in their chromatograms on the second and third incubation days. Furthermore, GC–MS analysis results revealed that the by-product formation during the phenanthrene degradation in all four Bacillus strains is identified as Phenol, 2-(phenylmethyl) (C13H12O) (molecular weight 184.0 g mol−1). Further HPLC analysis results revealed that nonetheless, that intermediate peak height gradually decreased until the sixth day, when it disappeared, indicating that some bacterial strains had completely degraded the by-products. According to the results, all four Bacillus spp. had greater than 50% of viability, confirming the non-toxicity of the by-products to the degrading bacterial strains. Furthermore, in toxicity assay with Vigna radiata, the appearance of the shoot and root from the seeds within 2 days confirmed that the highest concentration of by-product had no effect on seed growth and that the by-products produced were not harmful to the phyllosphere. Therefore, these phyllosphere Bacillus spp. can be used as efficient bioremediators which can clean phenanthrene-like polyaromatic hydrocarbon pollutants through phylloremediation. [ABSTRACT FROM AUTHOR]

Background Nile tilapia (Oreochromis niloticus) is predominant cultured species in aquaculture. However, there is a scarcity of literature regarding relationship between guava and star gooseberry leaf extract and the condition factor. Thus, the present study aims to investigate the effect of guava and star gooseberry leaf extract-supplemented diets on the specific growth rate, length-weight relationship, and condition factor of Nile tilapia. Methods Six hundred and thirty Nile tilapia (8.7±0.4 g) were randomly distributed among twenty-one tanks (30 fish per tank) within a recirculation system. Over a 60-day period, the fish were fed diets supplemented with 5g/Kg and 10g/Kg of guava leaf extract (GLE-5, GLE-10), star gooseberry leaf extract (SGLE-5, SGLE-10), and a mixture of both (MxLE-5, MXLE-10). Subsequently, specific growth rate, length-weight relationship, and condition factor were determined. Results After 60 days, the specific growth rate was significantly higher in all the GLE, SGLE, and MxLE groups compared to the control group. The final lengths and weights differed significantly both in the control group and all the GLE, SGLE, and MxLE groups. The analysis of the regression equation indicated a positive correlation (r = 0.970, 0.977, 0.976, 0.974, 0.974, 0.974, and 0.969) between the length and weight of Nile tilapia in the control group and in all the GLE, SGLE, and MxLE groups. The regression exponent "b" values in all the GLE, SGLE, and MxLE groups were >3, indicating a positive allometric growth pattern in Nile tilapia compared to the control (b=2.866), which exhibited a negative allometry. The final condition factor values did not differ significantly in either the control group or any of the plant extract groups. Conclusions Nile tilapia exhibited positive allometric growth patterns and maintained good health when fed with GLE, SGLE, and MxLE groups. Therefore, these plant extracts demonstrate suitability for commercial Nile tilapia production.

The lack of adequate assessment methods for pathogens especially in food is a critical problem in microbiology. Traditional predictive methods are not able to accurately describe the trend of low-density bacterial growth behavior observed in the laboratory. The purpose of this study was to leverage state-of-the-art of machine learning algorithms (MLA) to develop a predictive model for bacterial growth of Proteus mirabilis after treatment of bay leaf extract. The experimental data are fitted to three models, namely logistic, Gompertz, and Richard models. These models are trained using simulation data and a curve-fitting optimization algorithm in MATLAB called fminsearch is applied to the data to obtain the optimal parameters of the models. The results show that this method provides a breakthrough in bacterial growth modeling. Various forms of mathematical models such as Gompertz, Richard, and others are no longer necessary to model bacterial behavior. Additionally, the generated model can help microbiologists in understanding the growth characteristics of bacteria after disinfectant treatment, and provides a theoretical reference and a method of risk management for better assessment of pathogens in food.

The growth of cultured juvenile fish is usually quantified by two indexes, the specific growth rate or SGR, and the thermal-unit growth coefficient or TGC. The SGR is a relative growth index based on logarithms of body weights, and it decreases with body weight. The classical TGC is based on one-third powers of body weights and the summation of temperature over time. It can also depend on body weight, but it is possible to release this dependency by empirically adjusting the power function in its mathematical definition. These two indexes are usually presented in the same article to compare the growth attained by different groups of fish subjected to different experimental treatments. However, no formal framework linking both indexes is available for researchers up to the moment, the meanings of SGR and TGC remaining unrelated. The present work shows that the TGC of a group of fish growing at a given temperature can be expressed as a function of the SGR. In addition, the relationship between SGR and TGC here reported provides the basis to re-defined the TGC as a size-independent index with application to fish culture.

The growth performance and survival rates of juvenile striped catfish, Pangasianodon hypophthalmus, reared at various levels of pH and temperature were described in this article. Two rearing trials were conducted separately for pH and temperature where both trials lasted for 35 days. One hundred and twenty juveniles (1.5 ± 0.23 g) were randomly stocked into 12 rectangle glass aquariums (n = 10 fish/tank; three replicates per treatment) with 100 L of water for each trial. The treatment consisted of four different pH level (7.5, 8.0, 8.5 and 9.0) and four different temperature level (26 °C, 28 °C, 30 °C and 32 °C). The survival of fish was counted at the end of experiments, and the weight of the juvenile was measured once a week. The quantification of feed intake was determined through the measurement of the residual weight of the feeds after the feeding process. Upon the conclusion of the experiment, the data pertaining to weight and feed intake were utilized to calculate the specific growth rate (SGR) and food conversion ratio (FCR) as indicators of growth performance. Additionally, the number of live fish was employed to ascertain the survival rate. The data obtained from the calculation of SGR, FCR and survival rate were next subjected to a normality test, one-way analysis of variance (ANOVA), and a Tukey post-hoc test. The information in this article will help in the business, experimental, and personal usage for P. hypophthalmus juveniles rearing process.

Data variability complicates reproducibility and the interpretation of experimental results. Different animal models have been employed to decrease variability to enhance experimental power. However, variation frequently persists among and within strains/lines. In zebrafish (Danio rerio), inbred lines (e.g., NHGRI-1) derived from wild-type lines have been produced to greatly decrease genetic variation, with the goal of providing better understanding of genetic backgrounds that may influence the experimental outcome of studies employing such lines. We hypothesized that variations in morphological phenotypes shaped by environmental stressors early in development are correlated with the intrinsic degree of genetic variability of zebrafish lines. We compared morphological variability (yolk–chorion ratio, body mass, embryo mass, total length, condition factor, and specific growth rate) in wild-type AB and NHGRI-1 zebrafish lines as a function of their responses to altered temperature and oxygen availability during the first 7 days post-fertilization. Overall, both lines showed similar developmental trajectories for yolk–chorion ratio, embryo mass, and total length. Additionally, condition factor and specific growth rate showed similar responses within each line, regardless of temperature and hypoxia. Importantly, the coefficient of variation for each variable was significantly lower in NHGRI-1 than AB larvae for 151 of 187 assessed morphological endpoints. Thus, the low-heterozygosity NHGRI-1 zebrafish line can be useful for decreasing inter-individual variation in morphological responses to environmental stressors, thereby aiding in the interpretation of results and enhancing experimental reproducibility.

Cyanobacteria, photoautotrophic Gram-negative bacteria, play a crucial role in aquatic and terrestrial environments, contributing significantly to fundamental ecological processes and displaying potential for various biotechnological applications. It is, therefore, critical to identify viable strains for aquaculture and establish accurate culture parameters to ensure an extensive biomass supply for biotechnology purposes. This study aims to establish optimal laboratory batch culture conditions for Nostoc 136, sourced from Alga2O, Coimbra, Portugal. Preliminary investigations were conducted to identify the optimal culture parameters and to perform biomass analysis, including protein and pigment content. The highest growth was achieved with an initial inoculum concentration of 1 g.L−1, using modified BG11 supplemented with nitrogen, resulting in a Specific Growth Rate (SGR) of 0.232 ± 0.017 μ.day−1. When exposed to white, red, and blue LED light, the most favourable growth occurred under a combination of white and red LED light exhibiting an SGR of 0.142 ± 0.020 μ.day−1. The protein content was determined to be 10.80 ± 2.09%. Regarding the pigments, phycocyanin reached a concentration of 200.29 ± 30.07 µg.mL−1, phycoerythrin 148.29 ± 26.74 µg.mL−1, and allophycocyanin 10.69 ± 6.07 µg.mL−1. This study underscores the influence of light and nutrient supplementation on the growth of the Nostoc biomass.

Dietary supplementation of aquafeeds with functional additives is a commonly employed strategy in order to reduce the potential negative effects associated to fishmeal (FM) and fish oil (FO) replacement by alternative protein and oil sources. Nevertheless, the wide variety of functional ingredients with different bioactive properties hinders the selection of appropriate dietary supplementation strategies on feed formulation. The present study aimed to develop an observational multiple-linear regression (MLR) model to identify the effects of a variety of functional ingredients supplementation on European sea bass juveniles (Dicentrarchus labrax) growth performance and feed utilization. A literature survey was conducted gathering a total of 61 dietary treatments. The functional ingredients were classified in three main groups, namely, “probiotics”, “prebiotics” or “others” (including plant derived compounds such as essential oils, extracts and powders). Three different MLR were obtained and validated, allowing to describe the effects of functional ingredients supplementation on fish specific growth rate (SGR) (with a final R-squared (R2) = 0.96, adjusted R-squared (adj R2) = 0.92 and a p-value= 7.21E-08)), fish feed intake (FI) (R2 = 0.97, adj R2 = 0.95 and a p-value= 5.42E-12)) and fish feed conversion ratio (FCR) (R2 = 0.90, adj R2 = 0.80 and a p-value= 2.02E-05)). MLR model trimming, allowed the detection of a significant positive correlation (cor) between dietary prebiotics supplementation and SGR (cor= 0.32, p-value= 8.52E-04). On the contrary, prebiotic supplementation presented a negative correlation with fish FI (cor= −0.44, p-value= 6.27E-05) and FCR (cor= −0.41, p-value= 8.96E-05).

The freshwater angelfish (Pterophyllum scalare) is a quite popular freshwater ornamental fish in Indonesia due to its distinguished body shape and pattern. However, its growth tends to be slow due to low nutrients in its main diet, namely Daphnia magna. The most feasible solution is to enrich D. magna to increase its nutritional content with Viterna (livestock vitamins). The purpose of this study was to determine the effectiveness of D. magna enriched with Viterna to increase the growth of freshwater angelfish. This study used a Completely Randomized Design to compare three enrichment dosages (10, 20, and 30 ml/L) with a non-enriched control in three replications. This study showed that 3 hours-enrichment can result in an increase in fat (0.6%) and protein (1.25%) profiles in D. magna. Absolute Weight Growth (AWG), Absolute Length Growth (ALG), and Specific Growth Rates (SGR) showed significant differences (P=0.05) between all treatments. The best result was obtained at a Viterna dosage of 30 ml/L which resulted in an Absolute Weight Growth value of 207.14 mg, an Absolute Length Growth of 14.19 mm, and an SGR of 2.58%/day. Survival rates during the larvae culture were not statistically different (P=0.05) among the treatments. Enrichment of D. magna with Viterna has been proven to optimize its potential as live food for fish larvae cultivation. [ABSTRACT FROM AUTHOR]

Kinetic studies and modeling of production parameters are essential for developing economical biosurfactant production processes. This study will provide a perspective on mechanistic reaction pathways to metabolize Waste Engine Oil (WEO). The results will provide relevant information on (i) WEO concentration above which growth inhibition occurs, (ii) chemical changes in WEO during biodegradation, and (iii) understanding of growth kinetics for the strain utilizing complex substrates. Laboratory scale experiments were conducted to study the kinetics and biodegradation potential of the strain Pseudomonas aeruginosa gi |KP 163922| over a range (0.5–8% (v/v)) of initial WEO concentration for 168 h. The kinetic models, such as Monod, Powell, Edward, Luong, and Haldane, were evaluated by fitting the experimental results in respective model equations. An unprecedented characterization of the substrate before and after degradation is presented, along with biosurfactant characterization. The secretion of biosurfactant during the growth, validated by surface tension reduction (72.07 ± 1.14 to 29.32 ± 1.08 mN/m), facilitated the biodegradation of WEO to less harmful components. The strain showed an increase in maximum specific growth rate (µmax) from 0.0185 to 0.1415 h−1 upto 49.92 mg/L WEO concentration. Maximum WEO degradation was found to be ~ 94% gravimetrically. The Luong model (adj. R2 = 0.97) adapted the experimental data using a non-linear regression method. Biochemical, 1H NMR, and FTIR analysis of the produced biosurfactant revealed a mixture of mono- and di- rhamnolipid. The degradation compounds in WEO were identified using FTIR, 1H NMR, and GC–MS analysis to deduce the mechanism. [ABSTRACT FROM AUTHOR]

The lack of adequate assessment methods for pathogens especially in food is a critical problem in microbiology. Traditional predictive methods are not able to accurately describe the trend of low-density bacterial growth behavior observed in the laboratory. The purpose of this study was to leverage state-of-the-art of machine learning algorithms (MLA) to develop a predictive model for bacterial growth of Proteus mirabilis after treatment of bay leaf extract. The experimental data are fitted to three models, namely logistic, Gompertz, and Richard models. These models are trained using simulation data and a curve-fitting optimization algorithm in MATLAB called fminsearch is applied to the data to obtain the optimal parameters of the models. The results show that this method provides a breakthrough in bacterial growth modeling. Various forms of mathematical models such as Gompertz, Richard, and others are no longer necessary to model bacterial behavior. Additionally, the generated model can help microbiologists in understanding the growth characteristics of bacteria after disinfectant treatment, and provides a theoretical reference and a method of risk management for better assessment of pathogens in food. [ABSTRACT FROM AUTHOR]

Changes in the specific growth rate, as well as fluorescent, cytometric, and morphological parameters of the green microalgae Dunaliella salina, have been evaluated in the presence of Cu2+ ions (0–3750 µg/L) in a cultivation medium. The growth rate has been found to be the most sensitive to the copper presence; it decreases at copper concentrations above 150 µg/L, while an increase in the pollutant content to 1500 µg/L or higher results in the death of a microalgal culture. The number of algal cells at the stationary growth phase decreases as the copper content in the medium increases from 150 to 3750 µg/L. According to the results of this study, the efficiency of the algal photosynthetic apparatus is not affected by copper concentrations, which do not cause the death of the culture. A decrease in the values of the maximum fluorescence quantum yield, nonphotochemical quenching, and the maximum relative electron transport rate below the optimal values can be used as an indicator of the lethal impact of the studied pollutant on D. salina. Copper concentrations in the medium equal to 750 µg/L or higher cause the following effects: an increase in cell volume, an increase in the number of spherical cells, plasmalemma deformation and perforation, the predominance of deformed cells of an irregular shape, and a double reduction in the intracellular content of chlorophyll a and the specific yield of fluorescence for chlorophyll a (μg/L). [ABSTRACT FROM AUTHOR]

Pb is one of the most extensively used harmful heavy metals in Bangladesh, and its occurrence in waters affects aquatic organisms significantly. The tropical pearl mussel, Lamellidens marginalis, was exposed to different concentrations (T1 21.93 mgL−1, T2 43.86 mgL−1, and T3 87.72 mgL−1) of Pb(NO3)2 and was evaluated against a control C 0 mgL−1 of Pb(NO3)2, followed by a 96 h acute toxicity test. The LC50 value was recorded as 219.32 mgL−1. The physicochemical parameters were documented regularly for each treatment unit. The values of % SGR, shell weight, soft tissue wet weight, and weight gain remained statistically higher for the control group in comparison with the treatment. No mortality was noted for control units, while a gradually decreased survival rate was recorded for the different treatment groups. Fulton's condition factor was recorded as highest in the control and lowest in the T3 unit, while the condition indices did not vary between the control and treatment groups. The hemocyte was accounted as maximum in the control and T1, while minimum in T2 and T3. The serum lysosomal parameters also followed a similar pattern, and a significantly low level of lysosomal membrane stability, and serum lysosome activity was noted for T3 and T2 units in comparison to the control group. The histology of the gill, kidney, and muscle was well structured in the control group, while distinct pathologies were observed in the gill, kidney, and muscle tissue of different treatment groups. The quantitative comparison revealed that the intensity of pathological alteration increased as the dosage of Pb increased. The current study, therefore, indicated that intrusion of Pb(NO3)2 in the living medium significantly alters growth performance and hemocyte counts, and chronic toxicity induces histomorphological abnormalities in vital organs. [ABSTRACT FROM AUTHOR]

Phytogenic feed additives are plausible alternatives to antibiotics and serve as growth promoters in aquafeed. This research aims at finding the effects of varying inclusions of natural antioxidants like hibiscus (Hibiscus sabdariffa L.) and turmeric (Curcuma longa) on the growth, hematology, and nutrient utilization of Clarias gariepinus after 60 days of feeding. This research used six feeds labeled as F1-F6 that varied in the composition of C. longa and H. sabdariffa. The weight (g) inclusions of C. longa and H. sabdariffa were as follows, F1 0:250, F2 50:200, F3 100:15, F4 150:100, F5 200:50 and F6 250:0. Juvenile African catfish stocked at 9 catfish per 15L aquaria per 3 replicate aquariums (27/treatment feed) were fed for 60d. The catfish fed with F1 (250g H. sabdariffa) had the best specific growth rate of 5.76 ± 0.04 % day-1, lowest feed conversion ratio of 1.01 ± 0.01, weight gain of 31.65 ± 0.13 g, and protein efficiency ratio of 0.96 ± 0.07. The growth of African catfish increased with the increasing inclusion of hibiscus supplements. Hematobiochemical parameters ALT, AST was better for catfish fed high hibiscus supplements. We noticed that hibiscus inclusion was inversely proportional to cholesterol and total triglyceride levels of fish. The deposit of adipose tissues in the catfish was higher, with increasing inclusion of hibiscus than turmeric supplement. [ABSTRACT FROM AUTHOR]

Holopelagic Sargassum species have bloomed recurrently in the northern tropical Atlantic since 2011, causing socioeconomic and environmental problems. Little is known about their basic biology and responses to the abiotic environment. The aim of this study was to determine how temperature affects the growth rates of the genotypes S. fluitans III, S. natans I, and S. natans VIII that predominate in these blooms. The growth rates were evaluated in specially designed ex situ systems between 22 and 31 °C, which corresponds with the natural temperature range of these seaweeds in the northern tropical Atlantic. All the genotypes had decreased growth rates at 31 °C, and they varied in their response to temperature, with S. fluitans III presenting a maximal rate of 0.096 doublings· day−1 (doubling its weight in 10.5 d) at 28 °C and S. natans VIII a minimal rate of 0.045 doublings· day−1 (doubling its weight in 22.2 d) at 31 °C. In addition, the response to the temperature varied depending on the time of the year. Understanding the role of temperature in the growth of holopelagic Sargassum genotypes, amongst other factors influencing their physiology (such as nutrients, salinity tolerance, or light, including their interactions), could help to understand the dynamics of the recent blooms in the tropical North Atlantic.

In this study, an automatic control system is developed for the setpoint control of the cell biomass specific growth rate (SGR) in fed-batch cultivation processes. The feedback signal in the control system is obtained from the oxygen uptake rate (OUR) measurement-based SGR estimator. The OUR online measurements adapt the system controller to time-varying operating conditions. The developed approach of the PI controller adaptation is presented and discussed. The feasibility of the control system for tracking a desired biomass growth time profile is demonstrated with numerical simulations and fed-batch culture E.coli control experiments in a laboratory-scale bioreactor. The procedure was cross-validated with the open-loop digital twin SGR estimator, as well as with the adaptive control of the SGR, by tracking a desired setpoint time profile. The digital twin behavior statistically showed less of a bias when compared to SGR estimator performance. However, the adaptation—when using first principles—was outperformed 30 times by the model predictive controller in a robustness check scenario.

Sacharomyces cerevisiae contains about 45% protein but lacks some essential amino acids like methionine. Methionine promotes the growth of yeast and inhibits autophagy. We methionized yeast for 48hrs at 28°C and thereafter used it in the formulation of novel diets for hybrid African catfish "heteroclarias". The diets varied in the inclusion of methionine: Sacharomyces cerevisiae as follows; F1, 0:250; F2, 200:50; F3,150:100; F4, 100:150; F5, 50:200, and F6, 250:0. Hybrid catfish were stocked at 20 fish per aquaria, subjected to 12D:12L photoperiods and were fed ad libitum for 86 days. Hybrids that received feed F5 (200gyeast:50g Meth), had the highest SGR, 2.86±0.05 % day-1, lowest FCR F2, 1.04±0.08, highest weight gain 264.96±0.73g, highest PER 5.92±0.07 and highest DFI of 2.95±01g day-1. Conversely the hybrid fed diets F2 (200gMeth:50g yeast), had the lowest SGR of 0.97±0.01% day-1, highest FCR of 2.53±0.01, lowest weight of 35.03±7.52g, lowest PER 0.80±0.02 and lowest DFI of 0.47±0.02g day-1. All analyzed hematobiochemical indices were optimal for catfish fed F5 (200gyeast:50g Meth) and poorest for those fed F2(200gMeth:50g yeast). Results suggest that 50g kg-1 methionine inclusion and methionization of yeast is optimal and yields best growth, nutrient utilization and hematological parameters in diets of hybrid African catfish. [ABSTRACT FROM AUTHOR]

Smoltification is a key process in Atlantic salmon aquaculture, given it prepares the fish for a successful transit from fresh to seawater. However, industry players have not yet reached a consensus on the best protocols to produce high-quality smolts. In this study, we assessed how the combination of two photoperiod regimes in freshwater (continuous light or LL, and natural photoperiod or LDN) and four transfer times to seawater (February, March, April, and May) affected smolt development and their subsequent growth in seawater until slaughter during commercial production. The results demonstrated that smoltification and growth in freshwater were only slightly modulated by the photoperiod treatment and were instead much more affected by the limiting effect of the low water temperature during that period. In seawater, the growth rate was the highest in the same groups, which had, however, experienced a delay in growth when in freshwater, and consequently, no differences in the final body weight between the eight treatments were found. Such compensatory growth in the sea was probably enhanced by the increasing smolt quality, which could allow for better performance in seawater. A significant link between the weight at slaughter and weight at transfer was observed only in the groups with a lower smolt quality (LL-Feb, LDN-Feb and LDN-Mar), which suggests that larger individuals could cope better with a saline environment. In contrast, smaller smolts probably suffered greater osmotic stress that hindered their performance at sea. Afterwards, as smolt quality increased in the subsequent transfer groups, the relevance of this size effect decreased. This means that the industry may benefit from transferring larger smolts to seawater, especially if these are suspected of having developed suboptimal seawater tolerance. Those individuals are likely to cope better with saline conditions than smaller smolts. Future research should focus on the possible long-term effects of freshwater-rearing regimes on smolt performance in the seawater phase. [ABSTRACT FROM AUTHOR]