Dry Weight Measurements Research Articles

Utilization of fishery wastewater as a fertilizer and its impact on the growth performance of Spinacia oleracea (Spinach)

Aquaculture produces fishery wastewater (FWW), has polluted the environment and negatively impact the aquatic life. Utilizing FWW as a nutrient will promote sustainable agriculture and offer alternatives to conventional fertilizers. Some of the techniques used in water treatment, mainly the elimination of contaminants includes the use of screening, equalization tanks, aeration tanks, and sludge settling tanks before the treated water is released back to the environment or to be reused as a fertilizer. To evaluate the effects of the different FWW concentrations on the growth of spinach, the present study was carried out for 3.5 months using a complete randomized design with six groups of pot treatments that gave rise to 18 experimental units. Parameters such as height of plant, length of the root, number of leaves, fresh weight and the dry weight measurements were recorded. According to the experiments the pots which were treated with 20 ml FWW showed the best growth performance measures where shoot length was increased by 30% and root length by 60% compared to the control implying the prospect of the wastewater as a source of nutrients for agriculture. This research has implications toward the development of sustainable practices for both aquaculture and agriculture, in terms of reduction of global warming and climate change.

Utilization of Industrial Waste Casting Sands as Sustainable Building Material in Autoclaved Aerated Concrete Products

Autoclaved aerated concrete (AAC) is a building material with low density compared to traditional and structurally lightweight concrete. In addition to being very light, it is frequently preferred in many different areas, especially in external walls, floor slabs, lintels, roof slabs and panel elements of buildings, since it offers good heat and sound insulation. When the AAC production process is evaluated in terms of energy requirement, it has high environmental sensitivity compared to traditional concrete and brick processes. Since environmental sensitivity has become more important today, it was desired to evaluate the waste casting sands (WCS) generated in metal casting companies within the scope of the study. In this study, the usability of WCS as an alternative instead of silica sand used in AAC production was investigated. For this purpose, WCS was provided by 3 different casting companies. The usability potential of WCSs at 30% was examined and the quality of AAC was compared with reference castings. The fineness potentials of WCSs were compared by grinding in a disc mill. First of all, X-ray fluorescence spectrometry (XRF) and grain size analyses were performed on WCSs. 150x150x150 mm3 sized AAC laboratory samples were produced. The produced AAC samples were kept in the oven at 60°C until they set and then cured in an autoclave for approximately 10 hours. After the curing process in the autoclave, analyses such as compressive strength analyses and dry unit weight measurements were performed on the samples, and in addition to these analyses, they were subjected to visual examinations. Mechanical analyses were performed by replacing the WCS, from which positive results were obtained, at 5 different substitution ratios of 5, 10, 15, 20, and 30% by weight. From scanning electron microscope (SEM) and X-ray diffraction (XRD) analyses, it was determined that tobermorite structures were formed. From thermal analyses, it was observed that the thermal stability of the samples produced with WCS was better. When the results were evaluated in general, it was found that up to 30% WCS could be included in the AAC production system. In addition, an increase in compressive strength values occurred. The improvement in compressive strength also showed that WCS could be a good alternative source to silica sand.

Design, synthesis, molecular docking and antimicrobial evaluation of benzoylurea derivatives containing difluoromethyl (trifluoromethyl) pyrimidine.

The reduction in agricultural product quality and yield caused by fungal and bacterial plant diseases has led to considerable economic losses in global crop production and poses a threat to human health. The primary method of control remains the use of chemical agents. In an effort to develop novel and highly effective antimicrobial agents, a series of benzoylurea derivatives incorporating a difluoromethyl (trifluoromethyl) pyrimidine structure were designed and synthesized. In this study, we designed and synthesized a series of novel benzoylurea derivatives containing difluoromethyl (trifluoromethyl) pyrimidine fragments. Several of the synthesized compounds exhibited notable antifungal activity in vitro against PS, CBC, BBC and TBC. Their efficacy surpassed that of the positive controls HM and Pyr. Notably, 6s demonstrated an EC50 value of 4.10 μg mL-1, significantly lower than the 31.25 μg mL-1 for Pyr. In antibacterial assays, 6s also showed an 87.49% inhibition rate against Xoc. Moreover, in vivo tests against CBC revealed a protective efficacy of 59.39% at a concentration of 25 μg mL-1. Molecular docking simulations further supported its strong activity. To explore the mechanism of action of 6s on CBC, we conducted scanning electron microscopy, succinate dehydrogenase enzyme assays, and measurements of dry weight, membrane permeability, cellular contents, and ROS. This study underscores the potential of benzoylurea derivatives containing difluoromethyl (trifluoromethyl) pyrimidine fragments as lead compounds for the management of CBC. The results offer important insights and pave the way for the development of novel fungicides, contributing to improved crop protection strategies in agriculture. © 2024 Society of Chemical Industry.

Characterization of bio-crude produced by graphene carbon tetranitrate catalyzed hydrothermal liquefaction and ultrasonication of Ulva prolifera mixed Chicken waste

<p style="text-align:justify;"><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">The utilization of macroalgae, specifically </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, for the manufacture of bio-crude demonstrates great potential as a viable alternative to conventional fossil fuels. This is mostly owing to its abundant availability and renewable characteristics, making it an optimal choice for bio-oil production. This study examined the synthesis of bio-crude through the Hydrothermal Liquefaction (HTL) method. The combination of Ultra-sonicated </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, Chicken Waste, and water facilitated the transformation of the moist biomass into Bio-crude. The study also examined the influence of process parameters, including the optimal operational temperature, retention time, and feedstock mixing ratio (275 <sup>o</sup>C, 30 minutes, and 1:4 ratio) for the graphene-C<sub>3</sub>N<sub>4 </sub>catalyst, KOH. The study's findings verified that a significant amount of bio-oil, specifically 23.5wt.% based on dry weight measurements, was successfully produced. The bio-oil mostly consists of alcohols, esters, phenols, ketones, and acidic chemicals. Furthermore, the bio-oil exhibited a significant heating value of 38.15 MJ/kg, which can be attributed to the presence of carboxylic acid groups and aliphatic hydrocarbons. Furthermore, the carbon content in the bio-oil was found to be double that of the macroalgae used as feedstock. Additionally, the heating value of the bio-oil was shown to be 2.5 times greater than that of the macroalgae. Hydrothermal liquefaction may be used to efficiently create bio-oil from </span><em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">Ulva prolifera</span></em><span style="font-family:"Times New Roman",serif;font-size:12pt;line-height:200%;">, a third-generation fuel that has great potential as an environmentally benign and sustainable energy source.</span></p>

Leveraging the dynamics of microalgal CO2 capture to estimate the maximum inherent photosynthetic potential

AbstractBACKGROUNDNatural photosynthesis, utilizing intelligent molecular machinery to harness sunlight, stands as the benchmark for efficient energy generation. Despite its high quantum efficiency compared to synthetic methods, challenges persist due to dynamic nutritional and light requirements in plant, microalgae, and cyanobacteria‐driven processes. Reported microalgae CO2 uptake rates rely on biomass dry cell weight measurement after certain incubation period and systematic study of required CO2 concentrations for optimal photobioreactor operation remaining unexplored. This research is thus aimed at evaluating the critical dissolved CO2 (Ccrit ∙ CO2) concentration and specific CO2 uptake rates (SCUR) of Chlorella minutissima (CM) culture in the presence of surplus light and other nutrients by online monitoring and measuring the dynamic CO2 uptake rates which will help in maintaining the optimal rate of CO2 delivery for continuous cultivation of microalgae while minimizing the escape of CO2.RESULTSDissolved Ccrit ∙ CO2 was determined to be in the range of 16–20 mg/L, and the maximum SCUR in BBM (Bold Basal Medium) was found to be 0.73 mg CO2 (mg dcw ∙ h)−1. Interestingly, this SCUR value is nearly three times greater than that of the most efficient in vitro artificial photosynthetic novel pathway reported so far.CONCLUSIONFrom the calculated SCUR values, it may be noted that 9.6 g of biomass can be obtained from 1 g of microalgal inoculum in a day, thereby setting a benchmark for the scientists working in the areas of bioprocess engineering, synthetic biology, and metabolic engineering to comply. © 2024 Society of Chemical Industry (SCI).

The Influence of Varying Wavelengths of LED Light on the Development, Physiology Response, and Metabolism Activities of Micropropagated Dendrobium Hybrid ‘Shuijing’ Plantlets

Dendrobium hybrids have a significant role in the present floral sector. The aim of this research was to evaluate how various light qualities affect the physiological and biochemical traits of Dendrobium ‘Shuijing’. In order to determine the optimal light quality for in vitro cultivation of Dendrobium plantlets, we examined the correlations between growth, antioxidant capacity, and nutrient and chlorophyll levels, as well as chlorophyll fluorescence. The growth rate was compared by using different light qualities emitted by the LED light source. These included red light (R), blue light (B), and three ratios: 8R:2B, 7R:3B, and equal proportions of both colors, known as white, fluorescent light (CK). The combination of 7R:3B resulted in noticeable enhancements in leaf count, root length, root activity, fresh and dry weight measurements, antioxidant capability, as well as chlorophyll content and fluorescence. Specifically, the mixture of red and blue LED lights at a ratio of 7R:3B led to increased leaf number, root length, root activity, fresh and dry weight measurements, antioxidant ability, and chlorophyll content with improved fluorescence. In order to explore the effect of light quality on the growth and development of Dendrobium, the chlorophyll content and chlorophyll fluorescence parameters of plants under all light quality conditions were analyzed by using a linear regression model with other physiological and biochemical indexes. A significant correlation between non-photochemical quenching (NPQ) and leaf length was also observed. The content of chlorophyll b showed significant correlations with both root number and leaf number. Furthermore, chlorophyll a, along with its ratio to chlorophyll b, significantly correlated with root length. Chlorophyll b and the relative electron transport rate of PSII (ETRII) significantly correlated with root activity and the free proline content (FPC) and catalase (CAT) activity. The photochemical quenching coefficient (qP) significantly correlated with total soluble sugars content (SSC) and peroxidase (POD) activity. The correlation between the quantum yield of PSII (Fv/Fm ratio) and superoxide dismutase (SOD) activity was found to be significant. Similarly, the effective quantum yield of PSII photochemistry (ΦPSII) showed significant correlations with fresh weight, dry weight, soluble protein content (SPC), and ascorbate peroxidase (APX) activity. Through a principal component analysis (PCA), it was observed that plants cultivated under the 7R:3B light treatment achieved significantly better comprehensive scores compared to those grown under different light treatments. In conclusion, growth achieved under an LED emitting a ratio of 7R:3B light yielded the most robust Dendrobium hybrid plantlets within a controlled environment.

The effects of thinning on carbon and nutrient fluxes input into forest floor via litterfall in black pine afforestation sites.

As a component of the biogeochemical cycle, litterfall contributes carbon and nutrients to forest ecosystems by transferring organic material to mineral soil. Litterfall therefore serves as an important indicator for soil fertility and ecosystem health. This study aimed to determine the impact of different levels of thinning (light, moderate, and heavy) on litterfall quantity (needles, branches, bark, cones, and miscellaneous parts) and on the amount of carbon and nutrients entering the ecosystem in black pine afforestation areas. Three levels of low thinning, namely light, moderate, and heavy thinning (15%, 25%, and 35% of breast height area, respectively), were applied as treatments. Additionally, a control plot was included in the experiment. Litterfall samples were collected four times per year (once per season) from 12 treatment plots for three years. In the laboratory, dry weight measurements and analyses of carbon and macro-micro nutrient elements (N, P, K, Ca, Mg, S, Na, Fe, Cu, Zn, and Mn) were performed on litterfall samples taken from the field. Differences between treatments in terms of litterfall and the amount of carbon and nutrient elements entering the ecosystem were evaluated through variance analysis and the Duncan test. According to the findings, the quantity of litterfall input into the forest floor was highest in the control treatment, at 6,543kgha-1year-1 and lowest in the heavy treatment, at 4,378kgha-1year-1, showing a significant variation in litterfall quantity. The input of C to the soil ranged between 2,233kgha-1year-1 and 3,347kgha-1year-1 depending on thinning treatment. Although thinning treatment reduced C input to the soil, there was no significant difference among treatments. This also applied to nutrient elements such as N, P, K, Mg, and S. Needles constituted the majority of litterfall components (60%) and had the highest C density among all components, at 51.2%. The weighted carbon ratio for litterfall was calculated at 50.8%. Considering carbon-focused planning, performing moderate thinning interventions in the study area or similar pine-afforested areas may be a suitable option for maintaining the sustainability and health of the forest.

The effect of heavy metal lead (Pb) removal by Hydrilla verticillata, Hygrophila polysperma, and Rotala rotundifolia plants on the height and dry weight of plants

Heavy metal lead is widely used in the industrial world, such as in the manufacture of batteries and cable coatings. Behind its benefits, heavy metal lead has become a pollutant waste that is dangerous for the survival of organisms because it is accumulative and difficult to degrade. This study aims to analyze the effect of aquascape plants removing lead heavy metal concentrations on plant height and dry weight. The experimental design used in this study was a factorial complete randomized design with two factors. The results showed that the plants in all types of treatment had a bioconcentration factor (BCF) value > 1 so the three aquascape plants were categorized as accumulators. This study’s removal of lead and heavy metals influenced aquascape plants’ height and dry weight. The highest increase in height occurred in Hygrophila polysperma (A2B0), while the smallest increase in height occurred in Rotala rotundifolia (A3B0). Measurement of plant dry weight at the end of the study showed that Hydrilla verticillata had the highest dry weight of 1.26 g while the lowest dry weight was owned by Rotala rotundifolia plants at 0.34 g.

Dietary protein-to-carbohydrate ratio effects development and metabolism in Drosophila larvae and imago

Background. Nutrition during growth and development affects various traits not only in larvae but also imago including lifespan, reproduction, feeding, metabolism, and stress resistance. In this study, we have tested the hypothesis of whether the dietary protein-to-carbohydrate (P:C) ratio in the developmental diet could be related to subsequent changes in metabolic profile and physiological parameters in Drosophila larvae and imago. Materials and Methods. Drosophila melanogaster Canton-S strain were used in this study. Larvae were fed diets with different P:C ratios. Experimental media were composed of either 2 % or 5 % dry yeast and 0 %, 1 %, or 10 % of sucrose. We tested developmental rate, wet or dry body weight and the levels of certain metabolites inclu­ding glucose, glycogen, triacylglycerides and total lipids. The developmental rate was assessed by counting the number of generated pupae every 6/6/12 hours. For wet or dry weight measurement, 20 larvae or flies were weighed and transferred to plastic vial with a cut bottom. The flies were dried at 60 °C with the subsequent weighing after two days. Another two-day flies cohort were separated by sex and frozen in liquid nitrogen for further biochemical assays. Hemolymph glucose, total lipid concentration, triacyl­glycerides (TAG), body glucose and glycogen contents were determined spectrophotometrically. Results. We found that a low 0.08 P:C ratio in the diet slowed down pupation by ~20 % and decreased body weight in larvae. Hemolymph glucose levels in both larvae and imago were inversely associated with dietary P:C. Larvae developing on a diet with a low P:C ratio displayed a lower level of glycogen pool, but a higher level of lipids. Developmental dietary P:C ratio also influences metabolic traits such as hemolymph glucose, glycogen, TAG and total lipids in male and female imago. A higher total protein intake combined with restriction of sucrose consumption had glucose-lowering and lipids-lowering effects. Conclusions. Our study demonstrated that nutritional conditions during larval development trigger adaptive changes that provide a level of regulation necessary to surpass dietary stress in Drosophila imago.

An extended multiplicative error model of allometry: Incorporating systematic components, non-normal distributions, and piecewise heteroscedasticity.

Allometry refers to the relationship between the size of a trait and that of the whole body of an organism. Pioneering observations by Otto Snell and further elucidation by D'Arcy Thompson set the stage for its integration into Huxley's explanation of constant relative growth that epitomizes through the formula of simple allometry. The traditional method to identify such a model conforms to a regression protocol fitted in the direct scales of data. It involves Huxley's formula-systematic part and a lognormally distributed multiplicative error term. In many instances of allometric examination, the predictive strength of this paradigm is unsuitable. Established approaches to improve fit enhance the complexity of the systematic relationship while keeping the go-along normality-borne error. These extensions followed Huxley's idea that considering a biphasic allometric pattern could be necessary. However, for present data composing 10 410 pairs of measurements of individual eelgrass leaf dry weight and area, a fit relying on a biphasic systematic term and multiplicative lognormal errors barely improved correspondence measure values while maintaining a heavy tails problem. Moreover, the biphasic form and multiplicative-lognormal-mixture errors did not provide complete fit dependability either. However, updating the outline of such an error term to allow heteroscedasticity to occur in a piecewise-like mode finally produced overall fit consistency. Our results demonstrate that when attempting to achieve fit quality improvement in a Huxley's model-based multiplicative error scheme, allowing for a complex allometry form for the systematic part, a non-normal distribution-driven error term and a composite of uneven patterns to describe the heteroscedastic outline could be essential.

To Study the Effect of Integrated Weed Management Practices on Weeds Parameters of Transplanted Rice in Chhattisgarh Plains

The present experiment entitled “To study the effect of integrated weed management practices on weeds parameters of transplanted rice in Chhattisgarh plains” was studied during the 2022, kharif season at Agricultural Research Farm BTC, CARS, Bilaspur, Chhattisgarh. A randomized block design with ten treatments and three replications was used. Treatment T5 (untreated control) had the highest weed density and dry weight measurements, whereas treatment T6 (weed-free) had the lowest.The weed index was lowest in T6 (weed-free). The stage with the highest percentage of weed control efficiency was T6 (Weed-Free), then T10 (Chlorimuron ethyl 10% WP + Metsulfuron methyl 10% WP @ 0.06g ha-1 (20 DAT) + mechanical weeding (20 & 40 DAT) by Ambika paddy weeder at all stages.

Fabric Fiber as a Biofilm Carrier for Halomonas sp. H09 Mixed with Lactobacillus rhamnosus GG.

Biofilm bacteria have stronger resistance to the adverse external environment compared to planktonic bacteria, and biofilms of non-pathogenic bacteria have strong potential for applications in food. In this experiment, Halomonas sp. H09 and Lactobacillus rhamnosus GG, which have film-forming ability in monoculture and better film-forming ability in mixed culture than the two strains alone, were selected as the target strains for mixed culture. According to SEM observation and bacterial dry weight measurement, the target strain formed a dense biofilm on a 0.1g/L chitosan-modified cellulose III carrier. Furthermore, the presence of extracellular polymeric substances in biofilms was verified by EDS and FTIR. The results showed that 0.1g/L chitosan-modified cellulose III was an ideal carrier material for immobilization of Halomonas sp. H09 with Lactobacillus rhamnosus GG biofilm. This research provided a basis for the selection of non-pathogenic mixed-bacteria biofilm carriers.

Enhancing Chickpea (Cicer arietinum L.) Tolerance to Salinity through Plant Growth Regulators

During the period of 2020-21, a research study was carried out at the Plant Protective Culture Unit within the semi-controlled environmental settings of the Bangladesh Agricultural Research Institute. The aim of the study was to mitigate the negative impacts of salinity stress on chickpea by applying various concentrations of salicylic acid (SA) and gibberellic acid (GA3). Plants were subjected to four different levels of salinity stress, including a control group, mild stress, moderate stress, and severe stress. This was achieved by irrigating them with four varying concentrations of saline water (5, 7.5, 10 and 12.5 dSm-1) starting from the 14th day after sowing (DAS) and continuing until maturity at 100 DAS. On the other hand, the control plants received regular irrigation with tap water. Two concentrations of salicylic acid (SA) specifically 200 ppm and 400 ppm, along with gibberellic acid (GA3) at 10 ppm and 20 ppm, were administered as a foliar spray once a week, commencing at 20 days after sowing (DAS) and continuing until the flowering stage. Data related to chlorophyll levels in the leaves and water-related traits, including relative water content (RWC) and water retention capacity (WRC) were collected seven days after the foliar spray of these plant growth regulators at the flowering stage. Additionally, measurements of total dry weight, yield, and various yield-contributing factors were taken at the point of maturity. The results indicated that chickpea suffered adverse consequences due to salinity stress which included a reduction in chlorophyll content, a decrease in relative water content, a decline in water retention capacity, a decrease in total dry weight and a lower overall yield. However, the foliar application of different doses of salicylic acid (SA) and gibberellic acid (GA3) under varying levels of salinity stress had beneficial effects in alleviating the impact of salinity stress. Interestingly, it was observed that lower concentrations of SA at 200 ppm and GA3 at 10 ppm were more effective in mitigating the adverse effects of salinity stress and improving salinity tolerance in chickpea, especially under mild salinity stress conditions (5 dSm-1) as evidenced by the positive influence on the parameters mentioned above.

Mock samples resolve biases in diversity estimates and quantitative interpretation of zooplankton metabarcoding data

Metabarcoding is a rapidly developing tool in marine zooplankton ecology, although most zooplankton surveys continue to rely on visual identification for monitoring purposes. We attempted to resolve some of the biases associated with metabarcoding by sequencing a 313-b.p. fragment of the COI gene in 34 “mock” samples from the North Sea which were pre-sorted to species level, with biomass and abundance estimates obtained for each species and taxonomic group. The samples were preserved either in 97% ethanol or dehydrated for 24 h in a drying oven at 65 °C (the routine way of preserving samples for dry weight measurements). The visual identification yielded a total of 59 unique holoplanktonic and 16 meroplanktonic species/taxa. Metabarcoding identified 86 holoplanktonic and 124 meroplanktonic species/taxa, which included all but 3 of the species identified visually as well as numerous species of hard-to-identify crustaceans, hydrozoan jellyfish, and larvae of benthic animals. On a sample-to-sample basis, typically 90–95% of visually registered species were recovered, but the number of false positives was also high. We demonstrate robust correlations of relative sequence abundances to relative biomass for most taxonomic groups and develop conversion factors for different taxa to account for sequencing biases. We then combine the adjusted sequencing data with a single bulk biomass measurement for the entire sample to produce a quantitative parameter akin to species biomass. When examined with multivariate statistics, this parameter, which we call BWSR (biomass-weighed sequence reads) showed very similar trends to species biomass and comparable patterns to species abundance, highlighting the potential of metabarcoding not only for biodiversity estimation and mapping of presence/absence of species but also for quantitative assessment of zooplankton communities.

Anti-biofilm activity of a novel nanoemulsion containing Curcuma xanthorrhiza oil

ObjectivesWe aimed to solubilize Curcuma xanthorrhiza oil (CXO) using nanoemulsification and evaluate its inhibitory effects against biofilm formation. MethodsThe components of CXO were evaluated through high-performance liquid chromatography (HPLC) analysis. Healthy human saliva was inoculated onto hydroxyapatite discs to form microcosm biofilms for four days and treated six times with each antimicrobial agent: distilled water (DW), CXO emulsion (EM), CXO nanoemulsion (NE), and positive controls (Listerine and chlorhexidine). Biofilm fluorescence imaging was performed using quantitative light-induced fluorescence, and cell viability and dry-weight measurements were obtained. We compared the bacterial cell and extracellular polysaccharide (EPS) biovolume and thickness using confocal laser scanning microscopy (CLSM). ResultsHPLC analysis revealed that CXO was composed of approximately 47% xanthorrhizol. Compared with DW, NE exhibited significantly lower red fluorescence intensity and area (42% and 37%, p < 0.001 and p < 0.001, respectively), and reduced total and aciduric bacterial cell viability (7.3% and 3.9%, p < 0.001, p = 0.01, respectively). Furthermore, the bacterial cell and EPS biovolume and thickness in NE decreased by 40–80% compared to DW, similar to chlorhexidine. Conversely, EM showed a significant difference only in cell viability against total bacteria when compared with DW (p = 0.003), with EPS biovolume and thickness exhibiting higher values than DW. ConclusionsNanoemulsification successfully solubilized CXO and demonstrated superior anti-biofilm effects compared to the emulsion form. Clinical significanceThese findings suggest the potential use of NE as a novel antimicrobial agent for preventing oral diseases.

Zooplankton biomass, size structure, and associated metabolic fluxes with focus on its roles at the chlorophyll maximum layer during the plankton-contaminant MERITE-HIPPOCAMPE cruise

Recent studies have demonstrated that plankton can be a key pathway for the uptake and transfer of contaminants entering the marine environment up to top predators.The plankton-contaminant MERITE-HIPPOCAMPE cruise was devoted to quantifying contaminants in water and the whole plankton size range (10 size fractions) at 10 stations along a north-south transect in the western Mediterranean Sea from the French to the Tunisian coasts through the Provençal and Algerian basins. Pumping and filtering devices and net sampling have been used for collecting very high amounts of small particles and planktonic organisms in the chlorophyll maximum layer (CML). The present paper characterizes the zooplankton components for which the contaminant measurements were carried out. At each station, a horizontal towed Hydro-Bios net with a 60 μm mesh-size net was used to discriminate 5 size-fractions from 60 μm to a few mm. For each size-fraction, one part of the sample was used for dry weight measurements and the other one for estimating the contribution to biomass of detritus, phytoplankton, and among zooplankton of the major taxonomic groups based on the imagery tools ZOOSCAN and FLOWCAM. In each zooplankton size fraction, metabolic rates were calculated from the size spectrum to estimate trophic and excretion fluxes flowing through this fraction. These observations were compared to a similar analysis of tows in the upper layer (vertical) and the surface layer (horizontal).The total sampled biomass concentration at the CML was higher than in the water column (COL) and much higher than at the surface (SURF) in most of the stations, but in the CML and COL a substantial contribution was due to detritus mostly concentrated in the smallest size-fractions (60–200 μm and 200–500 μm). Absolute values of zooplankton biomass show neither a clear spatial pattern nor a significant difference between strata. The CML layer was dominated by copepods similarly to COL and SURF, but presented a higher contribution of nauplii and a near absence of appendicularians. At some stations, crustaceans and gelatinous plankton could be important contributors to CML. The zooplankton biomass composition of the two smallest fractions (<500 μm) was dominated by nauplii, small copepods and, occasionally, by small miscellaneous organisms (mostly pteropodes). In contrast, clear differences between stations appeared for the largest fractions (>500 μm) due to large crustaceans, gelatinous organisms, and chaetognaths. These changes in biomass composition according to size fractions suggest a progressive trophic shift from dominant herbivory in the smallest fractions to more contrasted trophic structure (including carnivory) in the largest fractions.The daily carbon demand and the N and P excretion of zooplankton were on average higher at the CML but with no significant difference with COL. The zooplankton grazing represented 2.7 to 22.7 % of the phytoplankton stock per day, whereas its excretion represented a daily N and P recycling compared to dissolved inorganic nitrogen and phosphorus stocks ranging respectively from 0.2 to 19 % and from 0 to 21 %. This information should help in the interpretation of the content of various contaminants in zooplankton fractions.

Real-time monitoring of biomass during Escherichia coli high-cell-density cultivations by in-line photon density wave spectroscopy.

An efficient monitoring and control strategy is the basis for a reliable production process. Conventional optical density (OD) measurements involve superpositions of light absorption and scattering, and the results are only given in arbitrary units. In contrast, photon density wave (PDW) spectroscopy is a dilution-free method that allows independent quantification of both effects with defined units. For the first time, PDW spectroscopy was evaluated as a novel optical process analytical technology tool for real-time monitoring of biomass formation in Escherichia coli high-cell-density fed-batch cultivations. Inline PDW measurements were compared to a commercially available inline turbidity probe and with offline measurements of OD and cell dry weight (CDW). An accurate correlation of the reduced PDW scattering coefficient µs ' with CDW was observed in the range of 5-69 g L-1 (R2 = 0.98). The growth rates calculated based on µs ' were comparable to the rates determined with all reference methods. Furthermore, quantification of the reduced PDW scattering coefficient µs ' as a function of the absorption coefficient µa allowed direct detection of unintended process trends caused by overfeeding and subsequent acetate accumulation. Inline PDW spectroscopy can contribute to more robust bioprocess monitoring and consequently improved process performance.

Characterization of diesel-degrading, hydrolytic enzymes-producing Streptomyces spp. isolated from fuel-oil polluted soils

Thirty-four different soil Streptomyces isolates previously recovered from soils of different gas stations that were historically polluted with fuel oil for long time were analyzed for their ability to produce five different hydrolytic enzymes, as well as for their potential to use diesel fuel as a sole carbon source for growth, in addition to the PCR amplification of the alkane hydroxylase gene (alkB). Results showed that 97.68% were producing at least one of the five hydrolytic enzymes, pectinase, carboxymethyl cellulase (CMCase), lipase, chitinase or amylase. Three isolates (1a, 5e, and 12a) were only producing all the tested enzymes and were able to use diesel fuel as a sole carbon source for growth as assessed by biochemical enzymatic assay and dry weight measurements. The capability of these isolates to use diesel as a sole carbon source for growth was obvious by changing the colourcolour of the reaction mixture within 6 hours, and the increase in dry weight after incubation for 28 days. Although the three isolates showed diesel degrading capability, they tested negative for harbouring the alkB gene by the PCR assay. alkB gene might not be the only gene responsible for alkanes degradation, and the isolates that grew on diesel and showed no PCR product might devoid the alkB gene.

Relationship Between Pigment Concentration and Dry Weight in Determining Microalgae Abundance in Artificial Water Samples

Microalgae are aquatic organisms that can function as bioindicators of surface water quality. The concentration of chlorophyll a can be measured to determine the level of microalgae abundance in a body of water. Measurement of the dry weight of microalgae biomass is another method that can be used to determine the abundance of microalgae in a body of water. Both methods have their advantages and disadvantages. In measuring chlorophyll concentration, the presence of other compounds besides chlorophyll which can absorb light spectrum at certain wavelengths (wavelengths of 665 nm, 645 nm, and 630 nm) causes the measured absorbance value to be greater than it should be. The level of turbidity due to the content of suspended particles in water is a problem in the dry weight measurement method. Determination of the dry weight of biomass based on the chlorophyll concentration approach is the subject of this study. The results of simple linear regression analysis showed that the concentration of chlorophyll a and the dry weight of microalgae biomass in treatment A had a fairly strong positive correlation (Ra = 0.870), the tendency of which was to follow the linear regression equation Y = 302.35x + 17.121. Determination of dry weight based on the chlorophyll concentration measurement approach can be applied to water samples with suspended solids content that tends to be constant and inert (does not produce substances that can react with organic solvents during the chlorophyll extraction process). In addition, based on the results of data processing it can be concluded that the effect of the content of other suspended particles in the water samples did not show a statistically significant effect.

Evaluation between lighting technologies on growing hydroponic lettuce

The use of lighting technologies combined with hydroponics has gained increased interest worldwide as a viable and integral horticultural solution to regions with limitations from geography or environmental conditions while offering scalability for rural cities, urban areas, and metropolitans alike. Unrelenting modern uncertainty with climate change, declining water and land supply; urbanization, and not to mention a population soon to exceed well over 8 billion in the coming decades will require innovative interdisciplinary solutions to secure sustainable food systems. In this study, we used a surrogate hydroponic garden to examine the difference in biomass yield from ambient sunlight (control) against supplemental High-Pressure Sodium (HPS) and Light Emitting Diodes (LEDs) lighting. Additionally, we determined the difference in irradiance, illuminance, and luminous intensity between the control and supplemental lighting treatments along with luminous efficacy between the latter. Both experimental groups exhibited higher total biomass of leaves and shoots than the control with measurement of wet and dry weight in grams. The LED group was found to have a significantly higher weight almost twice that of the HPS group. HPS and LEDs had significantly more luminous intensity, illuminance, and irradiance than the control but LEDs significantly outperformed HPS for all parameters including luminous efficacy.