Cells Ml-1 Research Articles

Simple and free-labeled voltammetry determination of glioma cell.

Glioma is one of the most frequent brain tumors with substantial mortality and morbidity, thus designing a simple sensor for achieving highly efficient determination of glioma cell is of great importance. In this work, by preparing 3,4,9,10-perylene tetracarboxylic acid (PTCA) non-covalently functionalized carbon black (CB) nanohybrids (CB-PTCA) as matrix and using angiopep-2 peptide (Ang-2) as receptor to recognize selectively glioma cell, a simple and free-labeled voltammetry sensor was developed for the first time to detect glioma cell by using Ang-2 and CB-PTCA modified glassy carbon electrode (Ang-2/CB/GCE): via introducing typical [Fe(CN)6]4-/3- as the signal probe, its electrochemical signal would be suppressed when glioma cells were recognized by Ang-2, and the values of peak current difference varied along with the concentrations of glioma cells. After optimizing the related testing conditions (the amounts of CB-PTCA, concentration of Ang-2 and recognition time of Ang-2 towards glioma cells), a wide linearity from 102 to 106 cells mL-1 and a low analytic limitation of 30 cells mL-1 were achieved for glioma cell. Furthermore, the application of the proposed immunosensor in human serum was also studied, revealing that the results are reliable and the designed proposal offers a significant clinical application for glioma detection.

The influence of H2 partial pressure on biogenic palladium nanoparticle production assessed by single-cell ICP-mass spectrometry.

The production of biogenic palladium nanoparticles (bio-Pd NPs) is widely studied due to their high catalytic activity, which depends on the size of nanoparticles (NPs). Smaller NPs (here defined as <100 nm) are more efficient due to their higher surface/volume ratio. In this work, inductively coupled plasma-mass spectrometry (ICP-MS), flow cytometry (FCM) and transmission electron microscopy (TEM) were combined to obtain insight into the formation of these bio-Pd NPs. The precipitation of bio-Pd NPs was evaluated on a cell-per-cell basis using single-cell ICP-MS (SC-ICP-MS) combined with TEM images to assess how homogenously the particles were distributed over the cells. The results provided by SC-ICP-MS were consistent with those provided by "bulk" ICP-MS analysis and FCM. It was observed that heterogeneity in the distribution of palladium over an entire cell population is strongly dependent on the Pd2+ concentration, biomass and partial H2 pressure. The latter three parameters affected the particle size, ranging from 15.6 to 560 nm, and exerted a significant impact on the production of the bio-Pd NPs. The TEM combined with SC-ICP-MS revealed that the mass distribution for bacteria with high Pd content (144 fg Pd cell-1 ) indicated the presence of a large number of very small NPs (D50=15.6nm). These results were obtained at high cell density (1 × 105 ± 3 × 104 cells μl-1 ) and H2 partial pressure (180 ml H2 ). In contrast, very large particles (D50=560 nm) were observed at low cell density (3 × 104 ± 10 × 102 cells μl-1 ) and H2 partial pressure (10-100 ml H2 ). The influence of the H2 partial pressure on the nanoparticle size and the possibility of size-tuned nanoparticles are presented.

Effects of different culture media on the growth and proximate composition of Dunaliella sp. at different growth phase

Nutrient content in different culture media significantly influence the growth and proximate content of microalgae. Therefore, in the present study Dunaliella sp. has been selected to determine its growth and proximate composition in different growth phase in Conway and F2 media. For growth determination, data were collected in terms of cell density and optical density and harvested in every growth phases to determine its proximate composition. Results concluded that, Dunaliella sp. showed higher cell density and earlier stationary phase in F2 medium with 7.8 x 106 cells mL-1 compared to the Conway media with 4.1 x 106 cells mL-1 . Significantly higher (p&gt;0.05) amount of protein content was recorded from Conway media in log phase with 67.58 % dry weight followed by lag and stationary phase with 57.53 % and 51.1 % dry weight. On the other hand, Dunaliella sp. showed no significant different (p&gt;0.05) in carbohydrate content at different growth phase but followed an increasing pattern with the growth of microalgae. Stationary phase showed the highest amount of carbohydrate compared with other phases with 19.78 % in Conway media and 23.93 % in F2 medium. Conway media resulted significantly higher (p&gt;0.05) lipid content compared to F2 medium. In lag, log and stationary phase 12.90 %, 9.80 % and 9.05 % of lipid were found in Conway media. This information might contribute to boost up the microalgal production by using the suitable culture media and can harvest the microalgae at different growth phases at their highest specific nutrient.

Fabrication of a Polyvalent Aptamer Network on an Electrode Surface for Capture and Analysis of Circulating Tumor Cells.

Capture and analysis of circulating tumor cells (CTCs) from complex matrixes is pivotal for the prediction of cancer metastasis and personalized treatment of cancer. Herein, we propose a strategy for CTC capture by design and fabrication of a polyvalent aptamer network on an electrode surface, which can be further used for the sensitive analysis of CTCs. In our design, the polyvalent aptamer network, which is constructed via a rolling circle amplification reaction, can significantly enhance the cell-binding abilities. Meanwhile, tetrahedral DNA structures previously assembled on the electrode surface will promote the spatial orientation and reduce the steric hindrance effect of the cell capture, thus improving the cell capture efficiency. Importantly, a detectable electrochemical signal can be obtained without additional signal probes by means of target-induced allostery of the DNA hairpin structures. Further studies reveal that the electrochemical response is proportional to the logarithm of the CTC abundance ranging from 102 to 5 × 104 cell mL-1 with a low limit of detection of 23 cell mL-1. Moreover, the proposed capture strategy exhibits excellent stability and anti-interference in human whole blood, indicating its promising potential in clinical diagnosis.

Iğdır Şartlarında Yetiştirilen Halep Keçilerinin Süt Verimi, Döl Verimi, Meme Özellikleri ve Çiğ Süt Somatik Hücre Sayısı

The aim of this study is to determine the somatic cell number (SCC), udder characteristics and some yield characteristics in Damascus goats. This study was carried out on the Damascus goats raised on a private farm brought the first time in Iğdır province of Turkey in 2013. In the study, 62 Damascus goats were measured SCC of 620 milk samples, monthly milk yields, and udder characteristics in 2019. In the study, mean values of some udder characteristics such as udder circumference, udder width, udder bottom height, udder upper height, teat angle, udder volume, teat diameter, and teat length were determined as 41.83±0.13 cm, 13.07±0.04 cm, 30.57±0.14 cm, 51.01±0.15 cm, 38.02±0.13º, 1754.84±10.65 ml, 6.09±0.09 mm and 5.44±0.06 cm, respectively. In raw milk, mean values of SCC and logarithmic Log10SCC were found as 503,120±40,020 cells ml-1 and 5,543±0.037 cells ml-1, respectively. The effect of birth type and lactation order on SCC and Log10SCC was found to be significant (p&amp;lt;0.01). Average daily milk yield, lactation length, and lactation milk yield, which are among the factors affecting milk yield, were found as 2.14±0.05 kg, 292.15±0.60 day, and 626.23±12.94 kg, respectively. The effect of lactation length and season on average dairy milk yield was found to be significant (p&amp;lt;0.01). The effects of udder type on lactation length (p&amp;lt;0.05), and lactation duration on lactation milk yield were found significant (p&amp;lt;0.01). As a result, it has been concluded that Damascus goats can be successfully raised under the conditions of Iğdır province.

Novel Ultrasensitive Photoelectrochemical Cytosensor Based on Hollow CdIn2S4/In2S3 Heterostructured Microspheres for HepG2 Cells Detection and Inhibitor Screening.

Hepatocellular carcinoma is a life-threatening malignant tumor found around the world for its high morbidity and mortality. Therefore, it is of great importance for sensitive analysis of liver cancer cells (HepG2 cells) in clinical diagnosis and biomedical research. To fulfill this demand, hollow CdIn2S4/In2S3 heterostructured microspheres (termed CdIn2S4/In2S3 for clarity) were prepared by a two-step hydrothermal strategy and applied for building a novel photoelectrochemical (PEC) cytosensor for ultrasensitive and accurate detection of HepG2 cells through specific recognition of CD133 protein on the cell surface with the respective aptamer. The optical properties of CdIn2S4/In2S3 were investigated by UV-vis diffuse reflectance spectroscopy (DRS) and PEC technology. By virtue of their appealing PEC characteristics, the resultant PEC sensor exhibited a wider dynamic linear range from 1 × 102 to 2 × 105 cells mL-1 with a lower limit of detection (LOD, 23 cells mL-1), combined by evaluating the expression level of CD133 protein stimulated by metformin as a benchmarked inhibitor. This work opens a valuable and feasible avenue for sensitive detection of diverse tumor cells, holding great potential in early clinical diagnosis and treatment coupled by screening inhibitors.

A high yield method for protoplast isolation and ease detection of rol B and C genes in the hairy roots of cauliflower (Brassica oleracea L.) inoculated with Agrobacterium rhizogenes

Protoplasts represent a unique experimental system for the circulation and formation of genetically modified plants. Here, protoplasts were isolated from genetically modified hairy root tissues of Brassica oleracea L. induced by the Agrobacterium rhizogenes strain (ATCC13332). The concentration of enzyme solutions utilized for protoplast isolation was 1.5 % Cellulase YC and 0.1 % Pectolyase Y23 in 13% mannitol solution, which resulted in high efficiency of isolation within 8 hours, in which the protoplast yield was 2 x 104 cells ml-1 and the percentage of viability was 72%. Each protoplast has one nucleus with a nucleation of 48%. A polymerase chain reaction (PCR) assay verified the presence of rol B and rol C genes in hairy root tissues by detaching a single bundle of DNA replication from these roots using a specific pair of primers. The current study demonstrated that A. rhizogenes strain (ATCC13332) is a vector for the incorporation of T-DNA genes into cauliflower plants, as well as the success of the hairy roots retention of rol B and rol C genes transferred to it.

Metabolic Engineering to Improve Docosahexaenoic Acid Production in Marine Protist Aurantiochytrium sp. by Disrupting 2,4-Dienoyl-CoA Reductase

Docosahexaenoic acid (DHA) has attracted attention from researchers because of its pharmacological and nutritional importance. Currently, DHA production costs are high due to fermentation inefficiency; however, improving DHA yield by metabolic engineering in thraustochytrids is one approach to reduce these costs. In this study, a high-yielding (53.97% of total fatty acids) DHA production strain was constructed by disrupting polyunsaturated fatty acid beta-oxidation via knockout of the 2,4-dienyl-CoA reductase (DECR) gene (KO strain) in Aurantiochytrium sp. Slight differences in cell growth was observed in the wild-type and transformants (OE and KO), with cell concentrations in stationary of 2.65×106, 2.36×106 and 2.56×106 cells mL-1 respectively. Impressively, the KO strain yielded 21.62% more neutral lipids and 57.34% greater DHA production; moreover, the opposite was observed when overexpressing DECR (OE strain), with significant decreases of 30.49% and 64.61%, respectively. Furthermore, the KO strain showed a prolonged DHA production period with a sustainable increase from 63 to 90 h (170.03 to 203.27 mg g−1 DCW), while that of the wildtype strain decreased significantly from 150.58 to 140.10 mg g−1 DCW. This new approach provides an advanced proxy for the construction of sustainable DHA production strains for industrial purposes and deepens our understanding of the metabolic pathways of Aurantiochytrium sp.

The Abundance and Potential Activity of Nitrifying, Denitrifying, and Nitrate-ammonifying Bacteria in the Vanamae Shrimp Culture in Karawang

The existence of inorganic nitrogen in the shrimp pond ecosystem will not be separated from the nitrogen cycle and microbiological processes including the activity of microbes. This study aimed to analyze the abundance and potential rate of nitrifying, denitrifying, and nitrate-ammonifying bacteria in Vanamae shrimp cultivation. Water samples were collected on a shrimp pond in Karawang, West Java. Water sampling was carried out at the age of shrimp rearing 0 days, 21 days, 65 days, and 89 days. Water sampling was conducted at four points representing an area of the pond. The bacterial abundances were analyzed using Most Probable Number (MPN) method. The potential rates of bacteria were calculated by Michaelis-Menten kinetics. The highest abundance of nitrifying bacteria was 3.690 log cells ml-1 on 65 days, denitrifying bacteria was 3.415 log cells mL-1 on 89 days, and nitrate-ammonifying bacteria was 3.079 log cells mL-1 on 65 days of shrimp cultivation. The affinity of enzymes related to ammonia oxidation from nitrifying bacteria was higher than nitrate reduction from denitrifying and nitrate-ammonifying bacteria. Generally, nitrifying bacteria were the most abundant and dominant activity over shrimp cultivation.

Development of an automatic system for cultivating the bioluminescent heterotrophic dinoflagellate &lt;italic&gt;Noctiluca scintillans&lt;/italic&gt; on a 100-liter scale

Noctiluca scintillans is a heterotrophic dinoflagellate that causes red-colored oceans during the day (red tides) and glowing oceans at night (bioluminescence). This species feeds on diverse prey, including phytoplankton, heterotrophic protists, and eggs of metazoans. Thus, many scientists have conducted studies on the ecophysiology of this species. It is easy to cultivate N. scintillans at a scale of &lt;1 L, but it is difficult to cultivate them at a scale of &gt;100 L because N. scintillans cells usually stay near the surface, while prey cells stay below the surface in large water tanks. To obtain mass-cultured N. scintillans cells, we developed an automatic system for cultivating N. scintillans on a scale of 100 L. The system consisted of four tanks containing fresh nutrients, the chlorophyte Dunaliella salina as prey, N. scintillans for growth, and N. scintillans for storage, respectively. The light intensities supporting the high growth rates of D. salina and N. scintillans were 300 and 20 μmol photons m-2 s-1, respectively. Twenty liters of D. salina culture from the prey culture tank were transferred to the predator culture tank, and subsequently 20 L of nutrients from the nutrient tank were transferred to the prey culture tank every 2 d. When the volume of N. scintillans in the predator culture tank reached 90 L 6 d later, 70 L of the culture were transferred to the predator storage tank. To prevent N. scintillans cells from being separated from D. salina cells in the predator culture tank, the culture was mixed using an air pump, a sparger, and a stirrer. The highest abundance of N. scintillans in the predator culture tank was 45 cells mL-1, which was more than twice the highest abundance when this dinoflagellate was cultivated manually. This automatic system supplies 100 L of N. scintillans pure culture with a high density every 10 d for diverse experiments on N. scintillans.

Paper-Based Cytometer for the Detection and Enumeration of White Blood Cells According to Their Immunophenotype.

Total and differential white blood cell (WBC) counts are vital metrics used routinely by clinicians to aid in the identification of diseases. However, the equipment necessary to perform WBC counts restricts their operation to centralized laboratories, greatly limiting their accessibility. Established solutions for the development of point-of-care assays, namely lateral flow tests and paper-based microfluidic devices, are inherently limited in their ability to support the detection of WBCs─the pore sizes of materials used to fabricate these devices (e.g., membranes or chromatography papers) do not permit passive WBC transport via wicking. Herein, we identify a material capable of the unimpeded transport of WBCs in both lateral and vertical directions: a coffee filter. Through in situ labeling with an enzyme-labeled affinity reagent, our paper-based cytometer detects WBCs according to their immunophenotype. Using two cultured leukocyte lines (Jurkat D1.1 T cells and MAVER-1 B cells), we demonstrate the specific, colorimetric enumeration of each target cell population across the expected physiological range for total lymphocytes, 1000-4000 cells μL-1. Additionally, we highlight a potential application of this type of device as a screening tool for detecting abnormal cell counts outside the normal physiological range and in subclasses of cell types, which could aid in the identification of certain diseases (e.g., CD4+ T lymphocytes, an important biomarker for HIV disease/AIDS). These results pave the way for a new class of paper-based devices─those capable of controlled white blood cell transport, labeling, capture, and detection─thus expanding the opportunities for low-cost, point-of-care cytometers.

Fungal Identification for Microalgae Biomass Hydrolysis using FTIR

Fungi offer a promising avenue for utilizing residual microalgae biomass after lipid extraction, harboring valuable carbohydrates that can be converted into useful compounds, such as sugars. Fourier Transform Infrared Spectroscopy (FTIR) stands out as an effective and environmentally friendly tool for selecting microorganisms with biotechnological potential. This study utilizes FTIR to identify suitable fungal strains for the hydrolysis of microalgae biomass (Desmodesmus subspicatus and Chlorella sp) post-lipid extraction. Eleven fungal strains are selected, applying FTIR and multivariate analysis to choose filamentous fungi. The maximum cell density is 28.7 × 106 cells mL-1 for Chlorella sp. and 15.8 × 106 cells mL-1 for D. subspicatus, with total carbohydrates of 23.1% and 16.9%, respectively. Principal Component Analysis (PCA) and Hierarchical Cluster Analysis (HCA) are useful for strain identification. Following the analysis, Penicillium G12 stands out for its ability to utilize D. subspicatus biomass, generating glucose and xylose (sugar yields of 9.4% and 6.6% respectively), and Trichoderma auricularis for Chlorella sp. (sugar yields of 12.9% and 9.6% respectively). FTIR proves successful in detecting fungal strains with biotechnological potential.

Assessment of the functional state and level of physical fitness of people with immunodeficiency virus with different levels of T-lymphocytes in the practice of a physical therapist

&#x0D; Purpose: to assess the functional state of patients with human immunodeficiency virus with different levels of T-lymphocytes for use in the practice of physical therapy.&#x0D; Materials and methods. We examined 24 patients with human immunodeficiency virus at the stage of acquired immunodeficiency syndrome at the outpatient stage of treatment. The patients were divided into 2 groups. Group 1 included 11 patients with CD4+ T-lymphocyte levels &lt;100 cells ml-1, and group 2 included 13 patients with CD4+ T-lymphocyte levels above 150 cells ml-1 (р&lt;0.01). The clinical and anamnestic data, the main anthropometric parameters and physiological indices, the results of carpal dynamometry, the 6-minute walk test, characterizing the functional state of people living with the human immunodeficiency virus, were studied. The results of immunological, virological and biochemical parameters were also studied.&#x0D; Results. Anthropometric indicators: Group 1 – body mass index 48.9±7.4 kg m2-1, waist to hip ratio ratio 0.92±0.17 cm, leg circumference 16.6±0.8 cm; Group 2 – body mass index 23.1±2.8 kg m2 -1, waist to hip ratio ratio 1.14±0.11 cm, leg circumference 15.9±1.4 cm (р&gt;0.05 ). Indicators of physiological indices: Reed - group 1 - 17.3±7.2%, group 2 - 18.3±11.8% (p&gt;0.05); Hobbes - group I 70.9 ± 5.5%, group 2 - 93.6 ± 11.8% (p&lt;0.05), Kerdo - group 1 was 26.6 ± 14.2%, group 2 - 10 .8 ± 14.7% (р&lt;0.05). Index of functional changes group 2 - 2.44±0.2 points, group 2 - 2.59±0.3 points (p&gt;0.05). Dynamometry indicators - group I - 17.5 ± 6.8 kg, group 2 - 28.1 ± 9.4 kg (р&gt;0.05); strength index – group 1 35.3±-9.6%, group 2 40.5±10.4% (р&gt;0.05); 6 min walk test in group 1 - 402.8±40.04 m, group 2 459.7±56.1 m (р&lt;0.05). Indicators of biochemical studies were in reference values ??in patients of both groups.&#x0D; Conclusions. There is a decrease in the functional state and the predominance of catabolic processes in people with human immunodeficiency virus with a significant deficiency of CD4+ T-lymphocytes.

Influence of culture medium on growth and protein production by Haematococcus pluvialis

Proteins from microalgal biomass have become promising raw materials in several industrial segments. To evaluate growth performance and protein production under different nutritional conditions, Haematococcus pluvialis was grown in different culture media: BBM, RM, BG-11, and KM2. The cultures were inoculated at 105 cells mL-1, and submitted to a temperature of 24°C, in a continous photoperiod and irradiance of 40 µmol photons m-2 s-1. The highest cell density was observed when H. pluvialis was maintained in BG-11 medium (142 ± 30 × 104 cells mL-1), but no statistical difference was observed when comparing the results with those obtained when culturing this microalga in BBM (101 ± 14 × 104 cells mL-1) and RM (105 ± 5 × 104 cells mL-1) media. Also, the lowest cell density was found when cultivating H. pluvialis in KM2 medium (57 ± 9 × 104 cells mL-1), and there was no statistical difference for doubling time, growth rate and specific growth rate results between treatments. In addition, higher protein contents in H. pluvialis were reported for RM, BG-11, and KM2 culture media at 55.1 ± 5.6, 49.3 ± 3.6 and 58.4 ± 2.8%, respectively; and lower protein content was found using the BBM medium (31.1 ± 2.9%). The highest cell density and biomass were achieved at greater nitrogen availability and a higher nitrogen to phosphorus ratio. The results suggest that H. pluvialis is a potential species for protein production, and that BG-11 is the most suitable medium for growing this microalga as it allowed the achievement of highest biomass production and protein content among the media evaluated.

Differences in the Composition of Abundant Marine Picoeukaryotes in the Marginal Sea Derived from Flooding

The transient impact of flooding on the community composition of marine picoeukaryotes (PEs, cell size ≤5 μm) in the East China Sea (ECS) was revealed in this study. In a summer without flooding (i.e., July 2009), photosynthetic picoeukaryotes (PPEs) were more abundant in the area covered by the Changjiang River diluted water (CDW, salinity ≤31) than in the non-CDW affected area. According to the 18S ribosomal RNA phylogeny, Alveolata (all from the superclass Dinoflagellata) was the main community component accounting for 72 to 99% of the community at each sampling station during the nonflooded summer. In addition to Dinoflagellata, diatoms or Chlorophyta also contributed a considerable proportion to the PE assemblage at the stations close to the edge of CDW coverage. In July 2010, an extreme flooding event occurred in the Changjiang River basin and led to the CDW covering nearly half of the ECS. In the flooded summer, the abundance of PPEs in the CDW-covered area decreased significantly to less than 1 × 104 cells ml-1. Compared to that during the nonflooded summer, the diversity of the PE composition was increased. While Dinophyceae still dominated the surface waters, Syndiniophyceae, which were represented by the uncultured Marine Alveolata Group (MALV)-I and MALV-II, accounted for a substantial amount in the Dinoflagellata superclass relative to this community composition in the nonflooded summer. Furthermore, a variety of plankton, including Cryptophyta, Haptophyta, Picobiliphyta, the uncultured Marine Stramenopiles (MASTs) and heterotrophic nanoflagellates, were observed. The nutrition modes of these PEs have been reported to be mixotrophic or heterotrophic. Therefore, it was inferred that the potentially mixotrophic and heterotrophic PE compositions might be favored in the marginal sea in the flooded summer.

Piscirickettsia salmonis forms a biofilm on nylon surface using a CDC Biofilm Reactor.

Research into Piscirickettsia salmonis biofilms on materials commonly used in salmon farming is crucial for understanding its persistence and virulence. We used the CDC Biofilm Reactor to investigate P.salmonis (LF-89 and EM-90) biofilm formation on Nylon, Stainless steel (316L), Polycarbonate and High-Density Polyethylene (HDPE) surfaces. After 144h of biofilm visualization by scanning confocal laser microscopy under batch growth conditions, Nylon coupons generated the greatest biofilm formation and coverage compared to Stainless steel (316L), Polycarbonate and HDPE. Additionally, P.salmonis biofilm formation on Nylon was significantly greater (p≤.01) than Stainless steel (316L), Polycarbonate and HDPE at 288h. We used Nylon coupons to determine the kinetic parameters of the planktonic and biofilm phases of P.salmonis. The two strains had similar latencies in the planktonic phase; however, LF-89 maximum growth was 2.5 orders of magnitude higher (Log cell ml-1 ). Additionally, LF-89 had a specified growth rate (µmax) of 0.0177±0.006h-1 and a generation time of 39.2h. This study contributes to a deeper understanding of the biofilm formation by P.salmonis and elucidates the impact of the biofilm on aquaculture systems.

Derivation of Ultrasonic Irradiation Condition to Inhibit the Growth of Microcystis aeruginosa

Objectives : The optimal ultrasonic irradiation conditions were derived through laboratory-scale experiments to evaluate growth inhibition effect of Microcystis aeruginosa (M. aeruginosa), which is the main specie of Cyanobacterial Harmful Algal Blooms (CyanoHABs) in Republic of Korea.Methods : The experiment was conducted by changing ultrasonic frequency, intensity, and initial cell concentration to observe the growth inhibition effect of M. aerginosa. The experiment was performed using shielded acrylic reactor [20 cm (W) × 20 cm (L) × 30 cm (H)]. Experiments were conducted using large volume (7.2 L) of water samples with high concentrations of M. aeruginosa, and the ultrasonic irradiation time was fixed at 3 hours.Results and Discussion : In all experiments, pictorial view of M. aeruginosa samples, chlorophyll-a (Chl-a) and cell number of M. aerginosa were observed. As a result of ultrasonic irradiation on M. aeruginosa, the decrease in both Chl-a concentration and cell number of M. aeruginosa was monitored after sonication compared to the decrease during sonication. In addition, the rebound growth was confirmed after certain period of growth inhibition of M. aeruginosa. The optimal ultrasonic irradiation conditions for the growth inhibition of M. aeruginosa were obtained at the lower frequency and the higher intensity. Whereas algal growth inhibition was observed with high concentration (4.5 × 106 cells mL-1) of M. aeruginosa, algal growth inhibition was not monitored with low concentration (1.1 × 106 cells mL-1) of M. aeruginosa.Conclusion : Through this study, the algal growth inhibition by ultrasonic was effective. Although the growth inhibition effect persisted for a certain period of time, subsequent regrowth was observed. Therefore, periodic ultrasonic irradiation is necessary for long-term growth inhibition of algal in field applications.

The Application of Chitosan as a Natural Flocculant Material to Chlorella sp. Abundance

Natural feed must be available in order to give high-quality seeds to support aquaculture activities. Chlorella sp. is a natural food source for fish larvae and zooplankton. Chlorella sp. is more effective and efficient when stored in the form of floc. The purpose of this research was to obtain an effective dose of chitosan for flocculation of Chlorella sp. The study used a completely randomized design (CRD) with 5 treatments and 3 replications, i.e A. 150 mg L-1, B. 200 mg L-1, C. 250 mg L-1, D. 300 mg L-1, E. 350 mg L-1. The abundance of Chlorella sp. before and after flocculation measured as the main parameter. Water quality parameter such as temperature, pH, dissolved oxygen, total ammonia nitrogen, and nitrite function as supporting parameters. The results showed that the abundance of Chlorella sp. before flocculation increased from the beginning of stocking until the 6th day. The best results of the abundance of Chlorella sp. found in the C treatment (54.4-74.5%), then followed with B, A, D, and E treatments (31.2-55.1%, 22.8-51.2%, 19.0-45.6 %, and 13.3-44.6%) respectively. The most effective dose of chitosan in the flocculation process of fresh water Chlorella sp. was 250 mg L-1 with an abundance of 39.1x105 cells mL-1. Water quality in culture media of the Chlorella sp. showed that the range of measured values were still within the optimum range.Keywords: Abundance, Chitosan, Chorella sp., Flocculation

Bioprinting of Cell-Laden Hydrogels onto Titanium Alloy Surfaces to Produce a Bioactive Interface.

The surface of metal implants serves as a powerful signaling cue for cells. Its properties play an essential role in stabilizing the bone-implant interface and facilitating the early osseointegration by encouraging bone deposition on the surface. However, effective strategies to deliver cells to the metal surfaces are yet to be explored. Here, a bioprinting process, called reactive jet impingement (ReJI), is used to deposit high concentrations (4 × 107 cells mL-1 ) of mesenchymal stromal cells (MSCs) within hydrogel matrices directly onto the titanium alloy surfaces that vary in surface roughness and morphology. In this proof-of-concept study, cell-hydrogel-metal systems are fabricated with the aim of enhancing bioactivity through delivering MSCs in hydrogels at the bone-implant interface. These results show that the high cell concentrations encourage quick cell-biomaterial interactions at the hydrogel-metal surface interface, and cell morphology is influenced by the surface type. Cells migrate from the hydrogels and deposit mineralized matrix rich in calcium and phosphorus on the titanium alloy surfaces. The authors demonstrate that ReJI bioprinting is a promising tool to deliver cells in a 3D environment before implantation that can be used when developing a new generation of medical devices for bone tissue engineering.

AN INVESTIGATION OF PHYSICOCHEMICAL PARAMETERS AND PHYTOPLANKTON COMMUNITY STRUCTURE OF EKO-NDE RESERVOIR IN OSUN STATE, NIGERIA

This research was carried out to determine the relationship between physicochemical variables and phytoplankton community of the Eko-Nde reservoir. Changes in physicochemical parameters of aquatic ecosystems have significant impact on the species that live therein. Eko-Nde reservoir is of socio-economic significance to communities that surround it, which necessitates a proper study of the phytoplankton composition and environmental status of the reservoir. Water samples were collected from two stations in the reservoir from January 2019 to August 2019. The physicochemical parameters that were determined include but not limited to temperature, total hardness, pH and biochemical oxygen demand. The composition and diversity of phytoplankton were analyzed. A total of 2039 cells ml-1 belonging to four (4) major divisions were dominant in the order; Bacillariophyta (898 cells ml-1) &gt; Charophyta (788 cells ml-1) &gt; Chlorophyta (302 cells ml-1) &gt; Cyanophyta (51 cells ml-1). Principal Component Analysis and Canonical Corresponding Analysis showed that certain physicochemical variables such as temperature, pH and total hardness were key drivers of the phytoplankton community structure of the reservoir. Diversity indices showed moderate abundance and distribution of phytoplankton species, with the highest diversity of species in the months associated with the rainy season. The appearance of pollution tolerant species such as Anabaena circinalis, Oscillatoria limosa, Nitzschia gracilis, Cymbella mexicana, Pediastrum boryanum, Synedra ulna, Cyclotella meneghiniana and Gomphonema spp. suggest that the reservoir was on the verge of pollution. Anthropogenic activities around the reservoir should be closely monitored to avoid health risks to humans and endangerment of aquatic organisms.&#x0D;