Differential Effect of Hydroxen Peroxide οn Toxic Cyanobacteria of Hypertrophic Mediterranean Waterbodies

Cyanobacterial blooms have been known since ancient times; however, they are currently increasing globally. Human and ecological health risks posed by harmful cyanobacterial blooms have been recorded around the world. These risks are mainly associated with their ability to affect the ecosystem chain by different mechanisms like the production of cyanotoxins, especially microcystins. Their expansion and their harmful effects have led many researchers to seek techniques and strategies to control them. Among them, hydrogen peroxide could be a promising tool against cyanobacteria and cyanotoxins and it is well-established as an environmentally friendly oxidizing agent because of its rapid decomposition into oxygen and water. The aim of the present study was to evaluate the effect of hydrogen peroxide on phytoplankton from two hypertrophic waterbodies in Greece. The effect of hydrogen peroxide on concentration of microcystins found in the waterbodies was also studied. Treatment with 4 mg/L hydrogen peroxide was applied to water samples originated from the waterbodies and Cyanobacterial composition and biomass, phycocyanin, chlorophyll-a, and intra-cellular and total microcystin concentrations were studied. Cyanobacterial biomass and phycocyanin was reduced significantly after the application of 4 mg/L hydrogen peroxide in water treatment experiments while chlorophytes and extra-cellular microcystin concentrations were increased. Raphidiopsis (Cylindrospermopsis) raciborskii was the most affected cyanobacterial species after treatment of the water of the Karla Reservoir in comparison to Aphanizomenon favaloroi, Planktolyngbya limnetica, and Chroococcus sp. Furthermore, Microcystis aeruginosa was more resistant to the treatment of Pamvotis lake water in comparison with Microcystis wesenbergii and Microcystis panniformis. Our study showed that hydrogen peroxide differentially impacts the members of the phytoplankton community, affecting, thus, its overall efficacy. Different effects of hydrogen peroxide treatment were observed among cyanobacerial genera as well as among cyanobacterial species of the same genus. Different effects could be the result of the different resistance mechanisms of each genus or species to hydrogen peroxide. Hydrogen peroxide could be used as a treatment for the mitigation of cyanobacterial blooms in a waterbody; however, the biotic and abiotic characteristics of the waterbody should be considered.

Catalase test for bacterial identification v1

Catalase is an enzyme that catalyzes the rapid decomposition of hydrogen peroxide into water and oxygen (2H2O2 + Catalase → 2H2O + O2). Organisms that do not present the catalase enzyme such as group B Streptoccoccus can not degrade hydrogen peroxide and therefore no bubble formation is observed.

Analysis of Ventilation Efficiency in the Earth Covered Magazine for Ammunition Storage Using Numerical Simulation

Internal environment parameters such as temperature, relative humidity and airflow velocity in ammunition storage facilities have a significant impact on the condition and overall life of ammunition, especially on the process of ammunition degradation in situations when their values deviate from required standards for safe storage. High temperatures inside the magazine, as well as in the ammunition packaging, can have a very negative effect on the structure of ammunition and explosives, and high values of relative humidity can result in corrosion and rapid decomposition of chemical compounds. Therefore, a properly designed ventilation system should ensure that the values of internal temperature and relative humidity are within the permitted limits, which is a very important aspect of the storage process itself, so that ammunition and explosives can be completely safe and ready for transport, use and handling. Experimental studies conducted in several magazines of ammunition and explosives in Bosnia and Herzegovina (BiH), had aim to monitor changes of environmental parameters such as temperature, relative humidity and airflow velocity. During these experimental measurements, high values of relative humidity were in these magazines observed, as well as uneven airflow in some ventilation ducks. The main cause of such measured values can be related to the inadequate performance of the natural ventilation system of the analysed magazines. Using numerical simulations (finite volume method) in the ANSYS – Fluent program, the analysis of the existing ventilation system of earth covered magazine in BiH from the aspect of airflow velocity was performed, as well as analysis of modifications that can improve airflow within the analysed magazine. The results of numerical simulation for the existing state of analysed magazine corresponded to the results of airflow measurements at certain places in the magazine. It was confirmed that the existing ventilation system does not provide proper ventilation, which further causes higher relative humidity values. The results of numerical simulation for the proposed modifications of the ventilation system have shown significantly better air circulation in the magazine, i.e. that a more efficient natural ventilation was achieved.

Potential use of Lupinus exaltatus Zucc. (Leguminosae) as green manure in soils of Jalisco, Mexico

The environmental impact generated by agriculture with excessive use of fertilizers has led to the search for alternatives to improve soil fertility. This study aimed to evaluate the potential of Lupinus exaltatus in terms of decomposition and mineralization of nitrogen (N) when incorporated into the soil as green manure (GM) and its effect on the growth of Triticum aestivum L. seedlings. Litter bags were used, with a total of 216 nylon bags (10 × 5 cm), in each bag were placed 5 g dry base of GM in the vegetative stage and flowering. Subsequently, the GM bags were placed separately Vertisol and Regosol soil at a depth of 5 cm; and every three weeks until the end of the incubation, three bags were recovered per treatment. For evaluation of the effect GM on T. aestivum growth experiment was established in pots with soil Regosol, it consisted of incorporating 50 and 34 g dry base of the GM (equivalent to 10 and 15 t.ha-1). The GM in the vegetative stage lost an average of 83,52 % of its initial weight, while in flowering the loss was 76,49 %, the mineralized N was higher in Regosol soil than in Vertisol with 74,02 % and 70,58 % respectively. The wheat seedlings presented 30 % more dry matter and N with GM than the control treatment. L. exaltatus had a rapid decomposition and mineralization of N in the first stages of incubation.

Valorisation of Fruit & Vegetable wastes: A Review

: Fruits and vegetables play an important part in the diets of global human population. During processing, the unused residues such as peels, stalks, rinds, stem, leaves etc. come out as waste. Due to the high moisture content of these perishable wastes, they undergo rapid decomposition that leads to foul odour and growth of pathogens. Almost, 30% of the loss occurs at the supply, retail, consumer, post-harvest and processing level. The perishable waste like peels, pomace, seeds etc. act as threat for the environment and degrade pollution-free model. The wastes are rich in protein, carbohydrates, minerals, vitamins and other phytochemicals and bioactive compounds such as pigments, dietary fibre, essential oils etc. Recent researches have shown that there is an increase in the utilization of these wastes for the extraction of value-added products such as bioactive compounds, bio-colorants, organic acids, Single cell protein (SCP), organic minerals, enzymes and others. The present review paper deals with the recent studies conducted on valorisation of the fruit & vegetable waste.

Revaluation of agri-food waste to obtain bioethanol

Objective: to produce bioethanol from the alcoholic fermentation of agri-food waste.Design/methodology/approach: food waste was collected for one month and separated into fruit and fabaceous waste; its size was reduced and then washed with hot acetone. A batch of 100 g of residue underwent acid hydrolysis with 5 %H 2 SO 4 at 125 °C, the hydrolysate was fermented with Saccharomyces cerevisiae at 30 °C for 48 h; the ferment was then distilled at 78 °C. The sugar content was determined following the phenol-sulfuric method. Brix degrees, density andpercentage w/w ethanol were measured with a densimeter.Results: from the fruit residues, an organic fraction was obtained with a total sugar content of 53.3 g/100 g of residue and 9.6 °Brix, generating 45 mL of distillate with 3.8 % w/w of bioethanol. From the fabaceae residues, an organic fraction was obtained with a total sugar content of 19.4 g and 4.140 °Brix, generating 30 mL of distillate with 2.54 % w/w of bioethanol.Study limitations/implications: Rapid decomposition of waste due to bacterial and fungal decomposition complicates long-term storage.Findings/conclusions: fermentable sugars can be obtained from the evaluated agri-food waste to obtain bioethanol. In this way, they can be integrated into the value chain as raw materials, reducing their accumulation and the environmental impact generated by their final disposal.

Liposomal IR-780 as a Highly Stable Nanotheranostic Agent for Improved Photothermal/Photodynamic Therapy of Brain Tumors by Convection-Enhanced Delivery

As a hydrophobic photosensitizer, IR-780 suffers from poor water solubility and low photostability under near infrared (NIR) light, which severely limits its use during successive NIR laser-assisted photothermal/photodynamic therapy (PTT/PDT). To solve this problem, we fabricate cationic IR-780-loaded liposomes (ILs) by entrapping IR-780 within the lipid bilayer of liposomes. We demonstrate enhanced photostability of IR-780 in ILs with well-preserved photothermal response after three repeated NIR laser exposures, in contrast to the rapid decomposition of free IR-780. The cationic nature of ILs promotes fast endocytosis of liposomal IR-780 by U87MG human glioblastoma cells within 30 min. For PTT/PDT in vitro, ILs treatment plus NIR laser irradiation leads to overexpression of heat shock protein 70 and generation of intracellular reactive oxygen species by U87MG cells, resulting in enhanced cytotoxicity and higher cell apoptosis rate. Using intracranial glioma xenograft in nude mice and administration of ILs by convection enhanced delivery (CED) to overcome blood-brain barrier, liposomal IR-780 could be specifically delivered to the brain tumor, as demonstrated from fluorescence imaging. By providing a highly stable liposomal IR-780, ILs significantly improved anti-cancer efficacy in glioma treatment, as revealed from various diagnostic imaging tools and histological examination. Overall, CED of ILs plus successive laser-assisted PTT/PDT may be an alternative approach for treating brain tumor, which can retard glioma growth and prolong animal survival times from orthotopic brain tumor models.

Study of Dissolved Organic Carbon Concentration in KHDTK Forest Peatland Area, Central Kalimantan, Indonesia

The study was conducted to determine whether are differences in dissolved organic carbon (DOC) in three different types of peatland conditions. The study was conducted from March 1st to April 30, 2020. The research was carried out in the Tumbang Nusa Special Purpose Forest Area (KHDTK). Furthermore, the analysis of DOC samples was carried out at the BALITRA Laboratory, Banjar Baru, South Kalimantan. The analysis of water pH samples was conduct at the UPT. LLG – CIMTROP, UPR Laboratory. The results showed that DOC in degraded peatlands site ranged from 36.18 mg L-1 to 76.86 mg L-1 with an average of 53.1 mg L-1, water pH between 3.6 to 4 with an average of 3.88, and the water table of 26.51 cm. Then in the forest site ranged from 37.12 mg L-1 to 49.81 mg L-1 with an average of 40.95 mg L-1, water pH ranged of 4 to 4.4 with an average of 4.32, and water table -5.13 cm. Furthermore, the re-vegetation site ranged from 29.27 mg L-1 to 34.90 mg L-1 with an average of 30.73 mg L-1, water pH between 4 to 4.3 with an average of 4.18, and water table 36.28 cm. Based on the results of the study it can be concluded that there is a difference in DOC in three sites, in the degradation site contributes higher dissolved organic carbon than other sites with an average amount of 53.1 mg L-1, compared to forest site with an average amount of 40.95 mg L-1, and re-vegetation site with an average amount of 30.73 mg L-1. Therefore, sustainable management of peat is expected to minimize the rapid decomposition of organic material in peat.

The OMZ and Its Influence on POC in the Tropical Western Pacific Ocean: Based on the Survey in March 2018

The hypoxia problem in the ocean is worsening, and the oxygen minimum zone (OMZ) continues to expand. The Tropical Western Pacific Ocean is one of the most sensitive areas in response to climate change and human activities, and the OMZ in this area has also expanded significantly. Based on a survey conducted in March 2018, the characteristics of OMZ in the Kocebu seamount area of the Tropical Western Pacific Ocean and its biogeochemical effects are discussed. The results showed that DO in the Kocebu seamount area first decreased and then increased, and the lowest value was 2.49 mg/L at a water depth of 750 m. Based on the oxycline and the threshold of 3.20 mg/L, OMZ in this area was located in the water column of 590–1,350 m. With the increase in water depth, the POC concentration decreased gradually and remained stable in the water column deeper than 1,000 m. The presence of OMZ reduced the decomposition rate of POC, causing more POC to sink into deeper waters. 38.77% of POC was decomposed in the water column of 150–300 m, whereas only 16.25% of POC was decomposed in the OMZ. In contrast to the vertical distribution of POC, δ13C-POC decreased rapidly in the water columns of 100–150 and 300–500 m, indicating the rapid decomposition of POC. This result suggests that POC and δ13C-POC should be combined in the evaluation of POC decomposition.