Laboratory Culture Research Articles

On a new species of ostracod from the Brazilian Amazon and its potential for experimental studies in laboratory culture

Ostracods are taxonomically and ecologically diverse small crustaceans that have recently gained prominence in laboratory studies and environmental impact assessment. In this context, the present study aims to assess the applicability of a new freshwater ostracod for experimental studies in the laboratory, and we provide the formal description of Strandesia rondoniensisn. sp. The original specimens for setting the laboratory cultures originated from the Natural Park of Porto Velho, in the Amazon region (Rondônia State, Brazil). The growth and reproductive rates of eleven adult individuals of S. rondoniensisn. sp. were analyzed. The results showed a high morphological resemblance with Neostrandesia striata and Bradleytriebella lineata, even though the new species belongs to Strandesia, indicating evolutionary convergence. The life cycle analysis showed that individuals of S. rondoniensisn. sp. have fast growth and high reproductive rates, which favour their use in laboratory studies. Besides contributing to the knowledge about ostracods in the Amazon region, which has been poorly studied, the life cycle experiment characterizations provided here should promote the use of this new species as a model organism for laboratory studies.

Tea (Camellia sinensis L. O. Kuntze) callus development based on morphological and phytochemical traits applied by variations in plant growth regulators (PGRs)

A variation of the clonal propagation system for tea has been established through in vitro methods, utilizing shoots and leaves derived from primary explants of mature field-grown plants. The research aimed to assess the diversity of tea calluses based on morphological and phytochemical traits derived from leaf and shoot explants on MS media induced by the application of plant growth regulators, including auxin and cytokinin. The research was conducted at the Seed Technology Unit Tissue Culture Laboratory, Faculty of Agriculture, Jatinangor, from April 2022 to February 2023. The experiment employed MS-modified multiplication media and PGR, with BAP at 9 mg/L, TDZ at 1.0 mg/L, Zeatin at 0.1 mg/L, NAA at 0.01 mg/L, and 1 mg/L. Results indicated that applying PGR, auxin, and cytokinin with MS media influenced morphological and phytochemical traits of tea's callus derived from leaves and shoots. Specifically, the treatment of 1 mg/L NAA + 1 mg/L BAP showed the best performance on callus weight and total phenolic and flavonoid contents compared to other treatments., i.e. 9.038% % and 0.05% %, respectively. The success of clonal propagation in tea through in vitro methods is expected to increase by carefully selecting the appropriate source and type of explant, planting media, PGR, and addressing potential contaminants.

In vitro characterization of probiotic potential of Lactobacillus plantarum CM49 against selected cattle mastitogens

BackgroundBovine mastitis results in significant economic losses for the dairy industry globally due to milk production losses and decreased herd efficiency. This research aimed to isolate, select, and characterize indigenous lactobacilli with probiotic properties. A total of 40 lactobacilli were isolated from healthy milk samples of cattle and identified at the species level through 16S rDNA sequencing. All isolates were initially screened for antimicrobial activity, and selected isolates underwent in vitro assessment of probiotic properties.ResultsAmong the lactobacilli isolates, varying levels of activity (9 to 19 mm) against cattle mastitogens; Stapylococcus aureus (Staph. aureus), Escherichia coli (E. coli) and Streptococcus dysgalactiae (Strep. dysgalactiae) were observed in the well diffusion assay. These isolates demonstrated auto-aggregation (ranging from 14.29 ± 0.96% to 62.11 ± 1.09%) and co-aggregate (ranging from 9.21 ± 0.14% to 55.74 ± 0.74%) with mastitogens after 2 h. Lactobacillus (Lb.) plantarum CM49 showed sensitivity to most antibiotics tested and exhibited strong inhibitory effects, with mean log10 reductions of 3.46 for Staph. aureus, 2.82 for E. coli, and 1.45 for Strep. dysgalactiae in co-culture experiments. Furthermore, Lb. plantarum CM49 significantly decreased the adhesion rate of mastitogens on the bovine mammary cell line and mouse model, demonstrating its potential effectiveness in preventing mastitis.ConclusionIt is concluded that Lb. plantarum CM49 has remarkable probiotic potential with activity against cattle mastitogens in the laboratory and cell culture and competitively excludes mastitogens from bovine mammary cells and ameliorates Staph. aureus-induced mastitis in mice.

Determination of Nasal and Endotracheal (ETT) Microorganisms in Pediatric Patients with Intubated VAP Admitted to the Pediatric Intensive Care Unit (PICU)

Background: Ventilator-associated pneumonia (VAP) is one of the most common healthcare-related infections in pediatric and neonatal intensive care units. In the present study, due to the importance of prevention, early identification, and treatment of VAP, nasal and endotracheal microorganisms were determined in intubated patients admitted to the pediatric intensive care unit. Objectives: The present study aims to determine the nasal and endotracheal (ETT) microorganisms in pediatric patients with intubated VAP admitted to the pediatric intensive care unit (PICU). Methods: This cross-sectional two-group case-control study was conducted on 90 intubated patients: Sixty patients with VAP (30 nasal, 30 tracheal tubes) and 30 patients without VAP, hospitalized in the PICU department of Amir al Mominin Ali (AS) Hospital in Zabol, Iran, from March 2018 to December 2018. The criteria for diagnosing VAP was the clinical pulmonary infection score (CPIS). In both case and control groups, samples were collected from nasal tubes using nasal swabs and from tracheal tubes (ETT) as tracheal aspirates from intubated patients, and sent to the laboratory for culture. The collected samples were interpreted in the microbiology laboratory to identify microorganisms. Data collection was done using a demographic information questionnaire and the clinical pulmonary infection score CPIS. The data was entered into SPSS 20 statistical software and analyzed. Results: The results of the present study showed that gender and age of patients do not affect the incidence of VAP, but children with VAP have a significantly longer stay in the PICU. Microbiological examination showed that Klebsiella and Escherichia coli (13.3%) were the most frequent among the positive nasal samples, and Klebsiella and E. coli (36.7%) were the most frequent among the positive tracheal samples. The diversity of microbes observed in ETT samples was also higher. Conclusions: The present study showed that the duration of hospitalization in the pediatric intensive care unit, as well as the age of hospitalized patients, can increase the risk of VAP. Additionally, nasal sampling is effective in identifying and differentiating VAP patients. It is suggested to reduce the duration of hospitalization in these departments as much as possible and to pay more attention to older children to prevent the increase of VAP. The results indicate that nasal bacteria play a role in the more severe occurrence of ventilator-induced pneumonia. Therefore, it is recommended to use broad-spectrum antibiotics and implement preventive nursing measures. If possible, starting feeding earlier through a gastric tube is also suggested.

Life history strategies of two springtails species (Hexapoda: Collembola) from saline soils

Springtails are a very common, widely spread component of soil fauna that play a significant role in numerous physical, chemical, and biological processes in the soil. Therefore, it is important to understand how their evolution and demographic parameters have changed throughout time. Since salinity is a relevant condition in the soils around the World and particularly in Mexico, the major goal of the current research is to understand the life cycle strategies of two springtail species from saline soils in Mexico. The studied species are Clavisotoma filifera and Brachystomella gabrielae, both widely distributed in Mexico, but their development or life history strategies are unknown. We found from laboratory cultures that C. filifera had a shorter life cycle and a faster reproduction rate than B. gabrielae. Nevertheless, both species show the same number of developmental stages, but there are interspecific differences in their duration. Although both species continuously reproduce throughout the year, the reproductive rate is lower in the months that are associated with the dry season at the source site. Additionally, we discovered variations in both the size and number of eggs in each species. It was found that the species under study had various life strategies for growth in the same environment. Clavisotoma filifera shows a more r-focused strategy (high fecundity, numerous offspring, shorter gestation and faster maturity), B. gabrielae shows an opposite strategy, closer to q strategy, with a lower fecundity, larger eggs, fewer reproductive events and slower maturity.

Exploration of Cinema Architecture to Resurge Cinema as a Cultural Laboratory in Malaysia

Exploration of Cinema Architecture to Resurge Cinema as a Cultural Laboratory in Malaysia

Application of the second-generation sequencing technology of metagenomics in the detection of pathogens in respiratory patients

ObjectiveTo explore the application value of the second-generation metagenomic next-generation sequencing (mNGS) in the detection of pathogens in patients with pulmonary infection. MethodsWe conducted a retrospective analysis of 65 pulmonary infection cases treated at our institution and the Fifth People's Hospital of Shanghai between January 2021 and May 2023. All subjects were subjected to mNGS, targeted next-generation sequencing (tNGS), and conventional microbiological culture. A comparative analysis was performed to evaluate the diversity and quantity of pathogens identified by these methodologies and to appraise their respective diagnostic capabilities in pulmonary infection diagnostics. ResultsThe mNGS successfully identified etiological agents in 60 of the 65 cases, compared to tNGS, which yielded positive results in 42 cases, and conventional laboratory cultures, which detected pathogens in 24 cases. At the bacterial genus level, mNGS discerned 9 genera, 11 species, and 92 isolates of pathogenic bacteria, whereas tNGS identified 8 genera, 8 species, and 71 isolates. Conventional methods were less sensitive, detecting only 6 genera, 7 species, and 33 isolates. In terms of fungal detection, mNGS identified 4 fungal species, tNGS detected 4 isolates of the Candida genus, and conventional methods identified 2 isolates of the same genus. Viral detection at the species level revealed 10 species and 46 isolates by mNGS, whereas tNGS detected only 3 species and 7 isolates. The area under the receiver operating characteristic curve (AUC) with 95% confidence intervals for diagnosing pulmonary infections was 0.818 (0.671 to 0.966) for mNGS, 0.668 (0.475 to 0.860) for tNGS, and 0.721 (0.545 to 0.897) for conventional culture.The mNGS demonstrates superior diagnostic efficacy and pathogen detection breadth in critically ill patients with respiratory infections, offering a significant advantage by reducing the time to diagnosis. The enhanced sensitivity and comprehensive pathogen profiling of mNGS underscore its potential as a leading diagnostic tool in clinical microbiology.

In-Vitro Growth of Transgenic Sengon Resulting From Co-Cultivation Using Agrobacterium Tumefaciens Bacteria

Sengon (Paraserianthes falcataria (L) Nielsen) is a forestry plant often developed for industrial purposes in Indonesia. Sengon is a fast-growing species and has a relatively short-cutting period. Sengon wood is widely used in the production of carpentry wood, plywood raw materials, and pulp. The purpose of this study was to optimize the transformation of the entC and pmsB genes into sengon plants using the embryo injury method through Agrobacterium tumefaciens as an intermediary and to determine the efficiency of the transformation using the injury to sengon embryos. This research was conducted from September 2022 to March 2023. The research was conducted at the Genetically Modified Organism (GMO) Tissue Culture Laboratory, Recombinant Protein (Microbe) Laboratory, and Greenhouse of the Genetic Engineering Center, National Research and Innovation Agency (BRIN) Cibinong, Bogor, Java West. The research procedure consisted of several steps, namely Preparation of MS Media, Preparation of LB Media, Preparation of Sengon Seed Infection Using Agrobacterium tumefaciens, Sterilization and Planting of Sengon Seeds, Acclimatization, and Molecular Analysis (including Sengon DNA isolation, PCR Amplification, and Electrophoresis). Transformation efficiency was calculated by the positive strain of hpt PCR bands compared to the number of transformed embryos and multiplied by 100%. In the results of the PCR analysis, it was found that one plant sample carried the hpt marker, which indicates the integration of the entC and pmsB genes. which when analyzed using transformation efficiency calculations, the data obtained for the entire transformation stage was 0.8%, where the success of the transformation obtained was still classified as low. Factors that cause the low success of transformation include the method of transformation, the growth phase of bacteria, genetic material, and culture aseptic conditions.

Suspended particulate matter in the Gulf of Oman: Spatial variations in concentration, bulk composition, and particulate metals controlled by physical and biogeochemical processes

The present work aims to assess the biogeochemical and physical sources of variation in the spatial distribution of suspended particulate matter (SPM), its major biotic and abiotic components, particulate metals, and the Redfield (N:P) stoichiometry of particles in a poorly understood basin of the Gulf of Oman. Particulate samples were collected in February 2022 from the Gulf of Oman aboard the R/V Persian Gulf Explorer, revealing surface SPM concentrations ranging from 140 to 1145 μg/l. The elemental composition of crustal-type elements in the surface offshore region confirmed the input of lithogenic components by aeolian dust from the surrounding deserts. The highest mid-depth SPM levels, with remarkable contribution from CaCO3, were observed at the western shelf edge at 100–300 m depth, supported by the Persian Gulf outflow. Conversely, mid-depth maxima with elevated concentrations of terrigenous elements were observed in the eastern edge, emanating from sediment resuspension and lateral transport under eddy-topography interaction. Organic matter is the most important phase, followed by biogenic silica from the basin-wide winter bloom of diatoms. While signs of CaCO3 dissolution are evident at depths >500 m, the oxidative precipitation of Mn (II) in the upper boundary of the oxygen minimum zone leads to the appearance of perceptible maxima in the vertical profile of particulate MnO2. Seasonal variations in the organic N:P ratio, from summer to winter, at the western station were linked to shifts in phytoplankton assemblage structure, transitioning from cyanobacteria dominance in summer to chain-forming diatoms in winter. The particulate pool of biologically important trace metals was dominated by a non-crustal fraction with enrichment factor followed a descending order: Cd > Mo > Pb > Zn > Ni in surface offshore samples. Metal/P ratios comparison with some previous data from the open ocean SPM and lab cultures of phytoplankton reveals that the Zn/P ratio is significantly exceeded in cultured communities, whereas the Cd/P ratio reflected the consistent demand in the Gulf of Oman compared to reported lab culture requirements.

Study of Aerobic Bacteria from Surgical Site Infection and their Antibiotic Susceptibility Pattern at a Tertiary Care Centre in Eastern Nepal

Background: The surgical site infections are the third most common nosocomial infection. The most common organism is Staphylococcus aureus. Nepal has a 4-7% overall prevalence rate for surgical site infection. The study objective was to find out the aerobic bacteria from surgical site infection and their antibiotic susceptibility pattern in a tertiary care hospital in Nepal. Materials and Methods: A descriptive cross-sectional study was conducted at a tertiary care center with effect from September 2022 to September 2023 approval from the Institutional Review Committee. Pus samples were taken from the postoperative wound infection site and submitted to the microbiological laboratory for culture and sensitivity. Gram-positive aerobic bacteria and gram-negative aerobic bacteria were isolated and identified by standard microbiological procedures. An antimicrobial susceptibility test was done on Muller-Hinton agar using the Kirby Bauer disc diffusion method. The result was interpreted according to clinical and laboratory standard institute guidelines. Results: The rate of surgical site infection was 22.24% and the most common organisms isolated were Staphylococcus aureus followed by Escherichia coli and Pseudomonas aeruginosa. All the gram-positive cocci were sensitive to linezolid, teicoplanin, and vancomycin and gram-negative bacteria were sensitive to meropenem, piperacillin/tazobactam, cefoperazone/sulbactam and cefepime. Conclusion: The present study concluded that the most common aerobic bacteria isolated from surgical site infection in our setting was found to be Staphylococcus aureus. This study also showed that the gram-positive aerobic bacteria were most susceptible tolinezolid, and teicoplanin, and gram-negative aerobic bacteria were sensitive to meropenem, piperacillin/tazobactam, and cefoperazone/sulbactam.

Visual detection of fungicide resistance by combining RPA and CRISPR/Cas12a in peach Brown rot fungus Monilinia fructicola.

Peach brown rot caused by Monilinia fructicola severely affects the quality and yield of peach, resulting in large economic losses worldwide. Methyl benzimidazole carbamate (MBC) fungicides and sterol demethylation inhibitor (DMI) fungicides are among the most applied chemical classes used to control the disease but resistance in the target pathogen has made them risky choices. Timely monitoring of resistance to these fungicides in orchards could prevent control failure in practice. In the current study, we developed methods based on recombinase polymerase amplification (RPA) and CRISPR/Cas12a systems to detect MBC and DMI resistance based on the E198A mutation in the β-tubulin (MfTub2) gene and the presence of the Mona element in the upstream region of the MfCYP51, respectively. For MBC resistance, RPA primers were designed that artificially incorporated PAM sites to facilitate the CRISPR/Cas12a reaction. Subsequently, specific tcrRNAs were designed based on the E198A mutation site. For the detection of the Mona element, we designed RPA primers M-DMI-F2/M-DMI-R1 that in combination with crRNA1 detected 'Mona' and distinguished resistant from sensitive strains. Both methods exhibited high sensitivity and specificity, requiring only a simple isothermal device to obtain results within 1 h at 37 °C. The FQ-reporter enabled visualization with a handheld UV or white light flashlight. This method was successfully used with purified DNA from lab cultures and crude DNA from symptomatic fruit tissue, highlighting its potential for on-site detection of resistant strains in orchards. © 2024 Society of Chemical Industry.

Toxicological properties of mixtures of binary silver-copper, silver-zinc, and copper nanoparticles on cell culture model and laboratory animals

The development, testing, and implementation of antimicrobial agents necessitates the determination of their toxicological characteristics. The objective of our research was to ascertain the direction and magnitude of the impact of experimental samples of disinfectants based on binary silver-copper, silver-zinc, and copper nanoparticles on biological entities of disparate levels of organization (cell culture, laboratory animals). The culture of calf coronary vessel cells (CVCs), 220 mature white laboratory rats, and 45 Chinchilla rabbits were used for the study. Mixtures of binary nanoparticles D1: MeNPs content – 5.4 mmol/L; D2: MeNPs content – 4.9 mmol/L were used as antimicrobial compounds. Toxic effects on cell culture were determined by the percentage of monolayer integrity, and biological effects in animals were determined by determining acute and subacute toxicity by clinical and biochemical parameters. The results of the culture studies demonstrated that the CC50 value of D2 was 6.2 times lower than that of D1, indicating a higher degree of cytotoxicity. No animal deaths were observed in the acute toxicity test (single intragastric administration to white rats at a dose of 30000 mg/kg body weight), which permitted the classification of the test samples as Class VI toxicity (relatively harmless) and Class IV hazardous (low-hazardous). When applied topically to rabbits' skin and mucous membranes, the experimental samples did not exhibit a pronounced irritant effect. A 30-day dermal application of the drugs to rats at doses of 0.5 and 5.0 mL/kg was conducted to determine the impact on hematological and biochemical parameters of a tenfold dose. Following the cessation of the administration of the aforementioned experimental disinfectant samples, the levels of all indicators were observed to return to the control levels within 14 days. The higher toxicity of the D2 drug for biological systems of different levels of organization, compared to the D1 drug, may be attributed to two factors: the higher concentration of AgNPs (2.4 times) and the potentiation of the toxic effect of two binary compounds (Ag-Zn and Ag-Cu) in its composition. Further research is needed to determine the biological impact of experimental samples of disinfectants based on silver, copper, and zinc metal nanoparticles on other functional systems of laboratory animals and the clinical and biochemical status of productive agricultural animals in production conditions.

Emergency control of dinoflagellate bloom in freshwater with chlorine enhanced by solar radiation: Efficiency and mechanism

Dinoflagellate requires a lower temperature and blooms frequently in the spring and autumn compared to regular cyanobacteria. The outbreak of dinoflagellate bloom will also lead to the death of some aquatic organisms. However, research on freshwater dinoflagellates is still lacking due to the challenges posed by classification and culture in laboratory. The removal effect and mechanism of Peridinium umbonatum (P. umbonatum, a typical dinoflagellate) were investigated using solar/chlorine in this study. The effect of simulated solar alone on the removal of algae was negligible, and chlorine alone had only a slight effect in removing algae. However, solar/chlorine showed a better removal efficiency with shoulder length reduction factor and kmax enhancement factor of 2.80 and 3.8, respectively, indicating a shorter latency period and faster inactivation rate for solar/chlorine compared to solar and chlorine alone. The removal efficiency of algae gradually increased with the chlorine dosage, but it dropped as the cell density grew. When the experimental temperature was raised to 30 °C, algal removal efficiency significantly increased, as the temperature was unsuitable for the survival of P. umbonatum. Attacks on cell membranes by chlorine and hydroxyl radicals (•OH) produced by solar/chlorine led to a decrease in cell membrane integrity, leading to a rise in intracellular reactive oxygen species and an inhibition of photosynthetic and antioxidant systems. Cell regeneration was not observed in either the chlorine or solar/chlorine systems due to severe cell damage or cysts formation. In addition, natural solar radiation was demonstrated to have the same enhancing effect as simulated solar radiation. However, the algal removal efficiency of solar/chlorine in real water was reduced compared to 119 medium, mainly due to background material in the real water substrate that consumed the oxidant or acted as shading agents.

Etiology, risk factors and antibiotic resistance in neonatal sepsis.

Objective: To determine the etiology, risk factors and antibiotic resistance in neonatal sepsis. Study Design: Cross-sectional study. Setting: Department of Pediatric Medicine, National Institute of Child Health, Karachi, Pakistan. Period: October 2023 to March 2024. Methods: A total of 174 neonates of both genders, with suspected neonatal sepsis were analyzed. Neonatal and maternal characteristics were noted. Blood sample was collected in aseptic environment and sent to institutional laboratory for blood culture and drug susceptibility testing. Results: In a total of 174 neonates, 101 (58.0%) were boys. The mean age, and weight were 9.61±7.86 years, and 2.25±0.85 kg, respectively. Neonatal sepsis on the basis of positive blood culture was reported in 38 (21.8%) neonates. Preterm birth had significant association with neonatal sepsis (44.7% vs. 26.5%, p=0.019). History of maternal UTI during pregnancy had significant linkage with neonatal sepsis (36.8% vs. 11.0%, p<0.001). History of maternal fever during pregnancy had statistically significant association with neonatal sepsis (34.2% vs/ 19.1%, p=0.049). E. Coli, and Klebsiella were the most commonly found bacterial isolates, noted in 8 (21.1%), and 4 (10.5%) neonates, respectively. Most commonly used antimicrobial drugs were found to have high resistance rates against most frequent bacterial isolates. Conclusion: E. Coli, and Klebsiella were the most commonly found bacterial isolates in neonatal sepsis. Preterm birth, maternal history of UTI, and maternal history of fever were found to be significant factors linked to neonatal sepsis. Most commonly used antimicrobial drugs were found to have high resistance patterns which should raise alarms.

Effects of different temperatures on the embryonic development of the Lebranche mullet Mugil liza.

We herein investigated the influence of temperature on theembryonic development (from fertilisation to hatching) of Mugil liza larvae. For this purpose, oocytes (>600 μm) and sperm were obtained from breeding stock at the laboratory of marine fish culture (LAPMAR). After fertilisation, 1200 eggs were distributed in 12 cylindrical experimental units of 400 mL under four different temperatures 18, 22, 26 and 30 ºC, all in triplicate. Every 15 min until hatching, about 10 eggs were randomly sampled in each treatment. The eggs were visualized and photographed, and the classification of embryonic stages was performed. Temperature influenced the main events of the embryonic development of M. liza. More accelerated development was observed according to the increase in temperature until the gastrula phase. At temperatures of 22 and 26 °C, embryonic development occurred from fertilisation to hatching of the larvae. In the 18 °C treatment, it was verified that most of the embryos ceased development during the final phase of cleavage and the beginning of blastula formation, while in the 30 °C treatment patterns of embryo malformation were also verified, with erratic divisions of the blastomeres, resulting in irregular cells. Unlike what was observed at a temperature of 18 °C, none of the embryos incubated at 30 °C reached the blastopore closure phase, stopping in the gastrula. The larvae hatched in the treatments at 22 and 26 °C were viable and exhibited intense swimming, with a large amount of reserve material (yolk) and an evident drop of oil.

Millisecond-scale behaviours of plankton quantified invitro and insitu using the Event-based Vision Sensor.

The Event-based Vision Sensor (EVS) is a bio-inspired sensor that captures detailed motions of objects, aiming to become the 'eyes' of machines like self-driving cars. Compared to conventional frame-based image sensors, the EVS has an extremely fast motion capture equivalent to 10,000-fps even with standard optical settings, plus high dynamic ranges for brightness and also lower consumption of memory and energy. Here, we developed 22 characteristic features for analysing the motions of aquatic particles from the EVS raw data and tested the applicability of the EVS in analysing plankton behaviour. Laboratory cultures of six species of zooplankton and phytoplankton were observed, confirming species-specific motion periodicities up to 41 Hz. We applied machine learning to automatically classify particles into four categories of zooplankton and passive particles, achieving an accuracy up to 86%. At the insitu deployment of the EVS at the bottom of Lake Biwa, several particles exhibiting distinct cumulative trajectory with periodicities in their motion (up to 16 Hz) were identified, suggesting that they were living organisms with rhythmic behaviour. We also used the EVS in the deep sea, observing particles with active motion and periodicities over 40 Hz. Our application of the EVS, especially focusing on its millisecond-scale temporal resolution and wide dynamic range, provides a new avenue to investigate organismal behaviour characterised by rapid and periodical motions. The EVS will likely be applicable in the near future for the automated monitoring of plankton behaviour by edge computing on autonomous floats, as well as quantifying rapid cellular-level activities under microscopy.

Impact of Engineered Metallic Nano-Oxides on the Growth and Development of Medicinal Crop <i>Carthamus tinctorious</i> L

Background: Nanotechnology has proved itself as a constructive as well as destructive step in the fields of medicine, agriculture, biosciences, pharmacology and engineering in the past three decades. As technology advances, so do diseases and other diverse inflammatory ailments in the modern world. Our daily health comes from the agricultural fields and surroundings. The increased metal toxicity and soil infertility are major causes of concern. Aim: This study aimed to analyse the growth requirements and impact of engineered metallic nano-oxide on the growth of a medicinal oil crop safflower (NARI -96) in a different but favourable geographical area (Rajasthan, India), unusual from its native geographical conditions. The major motive behind this study is to analyse the impact of metallic stress on yield and increase the crop production rate in Rajasthan for medicinal and economic benefit. Methods: The effect of discrete nano-oxides like silver, zinc, titanium and copper oxide with concentrations ranging from 00ppm to 80ppm have been evaluated on Carthamus tinctorius L. The study was conducted in a controlled environment in a Plant Tissue Culture (PTC) lab as well as in greenhouse conditions. Results: The foremost results in the PTC method have been found with the treatment of copper and zinc oxide. The silver oxide showed a toxic effect and retard the growth. The plant growth under normal environmental conditions showed different results due to the alkaline nature of the soil. The efficiency of titanium oxide and copper oxide has been showing better morphophysiological results in comparison to the control and other nano-oxides. Conclusion: The study reveals that metallic nano-oxides greatly influence the growth and development of safflower under controlled as well as in greenhouse conditions but the impact of copper oxide remains constant in both conditions.

Construction of an expression platform for fungal secondary metabolite biosynthesis in Penicillium crustosum

Filamentous fungi are prolific producers of bioactive natural products and play a vital role in drug discovery. Yet, their potential cannot be fully exploited since many biosynthetic genes are silent or cryptic under laboratory culture conditions. Several strategies have been applied to activate these genes, with heterologous expression as one of the most promising approaches. However, successful expression and identification of new products are often hindered by host-dependent factors, such as low gene targeting efficiencies, a high metabolite background, or a lack of selection markers. To overcome these challenges, we have constructed a Penicillium crustosum expression host in a pyrG deficient strain by combining the split-marker strategy and CRISPR-Cas9 technology. Deletion of ligD and pcribo improved gene targeting efficiencies and enabled the use of an additional selection marker in P. crustosum. Furthermore, we reduced the secondary metabolite background by inactivation of two highly expressed gene clusters and abolished the formation of the reactive ortho-quinone methide. Finally, we replaced the P. crustosum pigment gene pcr4401 with the commonly used Aspergillus nidulans wA expression site for convenient use of constructs originally designed for A. nidulans in our P. crustosum host strain. As proof of concept, we successfully expressed a single polyketide synthase gene and an entire gene cluster at the P. crustosum wA locus. Resulting transformants were easily detected by their albino phenotype. With this study, we provide a highly efficient platform for heterologous expression of fungal genes.Key pointsConstruction of a highly efficient Penicillium crustosum heterologous expression hostReduction of secondary metabolite background by genetic dereplication strategyIntegration of wA site to provide an alternative host besides Aspergillus nidulansGraphical

Isolation of a methyl-reducing methanogen outside the Euryarchaeota.

Methanogenic archaea are main contributors to methane emissions, and have a crucial role in carbon cycling and global warming. Until recently, methanogens were confined to Euryarchaeota, but metagenomic studies revealed the presence of genes encoding the methyl coenzyme M reductase complex in other archaeal clades1-4, thereby opening up the premise that methanogenesis is taxonomically more widespread. Nevertheless, laboratory cultivation of these non-euryarchaeal methanogens was lacking to corroborate their potential methanogenic ability and physiology. Here we report the isolation of a thermophilic archaeon LWZ-6 from an oil field. This archaeon belongs to the class Methanosuratincolia (originally affiliated with 'Candidatus Verstraetearchaeota') in the phylum Thermoproteota. Methanosuratincola petrocarbonis LWZ-6 is a strict hydrogen-dependent methylotrophic methanogen. Although previous metagenomic studies speculated on the fermentative potential of Methanosuratincolia members, strain LWZ-6 does not ferment sugars, peptides or amino acids. Its energy metabolism is linked only to methanogenesis, with methanol and monomethylamine as electron acceptors and hydrogen as an electron donor. Comparative (meta)genome analysis confirmed that hydrogen-dependent methylotrophic methanogenesis is a widespread trait among Methanosuratincolia. Our findings confirm that the diversity of methanogens expands beyond the classical Euryarchaeota and imply the importance of hydrogen-dependent methylotrophic methanogenesis in global methane emissions and carbon cycle.

The resting cyst of dinoflagellate Scrippsiella acuminata host bacterial microbiomes with more diverse trophic strategies under conditions typically observed in marine sediments.

Variation in the condition of marine sediments provides selective preservation milieus, which act as a key determinant for the abundance and distribution of dinoflagellate resting cysts in natural sediments. Microbial degradation is an understudied biological factor of potential importance in the processes. However, gaps remain in our knowledge about the fundamental information of the bacterial consortia associated with dinoflagellate resting cysts both in laboratory cultures and in the field. Here we used Scrippsiella acuminata as a representative of cyst-producing dinoflagellates to delineate the diversity and composition of bacterial microbiomes co-existing with the laboratory-cultured resting cysts, and to explore possible impacts of low temperature, darkness, and anoxia (the mock conditions commonly observed in marine sediments) on the associated bacterial consortia. Bacterial microbiome with high diversity were revealed associated with S. acuminata at resting stage. The mock conditions could significantly shift bacterial community structure and exert notably inhibitory effects on growth-promoting bacteria. Resting cysts under conditions typically observed in marine sediments fostered bacterial microbiomes with more diverse trophic strategies, characteristic of prominently enriched anaerobic chemotrophic bacteria generating energy via respiration with several different terminal electron acceptors, which yielded more acidic milieu unfavorable for the preservation of calcareous resting cysts. Our findings suggest that there is complex and dynamic interaction between dinoflagellates resting cysts and the associated bacterial consortia in natural sediments. This intrinsic interaction may influence the maintenance and/or accumulation of dinoflagellate resting cysts with potential of germination and initiation blooms in the field.