Influence of nano-activated carbon on biodegradation of bamboo paper in the soil

Paper made from natural fiber of ampel bamboo (Bambusa vulgaris) and nano-activated carbon from sawdust had been tested as food packaging and showed its ability to maintain freshness and nutritive value of foodstuffs. However, as a packaging material, natural degradability of this alternative natural-fiber paper is required to be tested. This study aims to determine the effect of nano-activated carbon on paper’s biodegradation properties. The results showed that paper treated with nano-activated carbon degraded faster in the soil compared to paper made of bamboo fiber only (control) after 8 weeks of observation. The microorganism population density analysis showed that the paper with nano-activated carbon had a lower microorganism density than the control which accompanied by a decrease in paper weight after 12 weeks of observation. This finding demonstrates the potential utilization of nano-activated carbon as an additive to be inserted into paper to accelerate the biodegradation rate of paper in the soil. The ability of paper to be degraded naturally is very important to support environmental sustainability.

Periodic Solution of a Stochastic Microorganism Flocculation Model with Distributed Delay

In this paper, a nonautonomous delay differential equation of microorganism flocculation is established by considering the influence of external conditions such as seasonal alternation and ocean current movement on the ecological function of microorganism population. At the same time, the dynamic change characteristics of microorganism population in oil spill environment were simulated, and on this basis, the effects of diurnal change and climate change on the parameters of microorganism system were analyzed. From a mathematical point of view, the stochastic microorganism flocculation model exists a T-positive periodic solution. The existence and uniqueness of globally positive equilibrium of the exploited model is studied. Finally, some numerical examples illustrate the results.

Evaluation of the efficiency of a low-cost aerator and water quality in intensive production systems of tilapia with bioflakes at different stocking densities

Among the types of production systems applied in aquaculture, the biofloc culture system (BTF) has been gaining space due to its sustainable techniques. Noteworthy is the low or zero renewal of water, the formation of the microorganism population predominantly autotrophic and heterotrophic, resulting in microbial flakes. Taking into consideration the effectiveness of the system in tilapia farming, this work aimed at the fabrication, implementation, and analysis of the efficiency of a low-cost aerator. To evaluate and control the physical and chemical parameters of the water, 3,780 Nile tilapia fry were used with an initial average biomass of 3±0.5g, distributed in 24 rectangular tanks with a useful volume of 125 liters. The experiment included 6 treatments (T1: 360 fish m-3, T2: 1800 fish m-3, T3: 1080 fish m-3, T4: 1440 fish m-3, T5: 720 fish m-3 and T6: 2160 fish m-3) and four repetitions. The efficiency of the Venturi effect aerator and the water quality parameters were analyzed. Comparisons of the averages were performed using Tukey's test at 5% significance. From the dissolved oxygen analysis, it was possible to conclude that the aerator Venturi effect was efficient during the experiment, meeting the desired levels, also taking into consideration the ease of applicability and low cost for its development. Through the analysis of the physical-chemical parameters of the water and the mortality rates during the experiment, it can also be concluded that the safest density to operate using the bioflocci is up to 720 fish m-3.

The Effect of Different Regimens of Vaccination against Pneumococcal Infection on the Clinical Course of Chronic Obstructive Pulmonary Disease: Focus on Changes in Sputum Microorganism Population

The objective: development of the best vaccination regimen against pneumococcal infection in patients with chronic obstructive pulmonary disease (COPD) with consideration of changes in microbiological and clinical parameters.Subjects and Methods. 115 patients with COPD were randomized into 4 pneumococcal vaccination groups, they were examined and followed up for 4 years; 112 patients completed the study complying with the protocol. Detail medical history of all subjects was collected. To verify the diagnosis of COPD, all subjects underwent external respiratory function test and bronchodilator test (salbutamol, 400 μg) according to the standard method. The classic microbiological assessment was used in this study. The clinical effectiveness of vaccination was assessed. Statistical processing of the results was performed using StatPlus Pro 6.2.0.0 software (license number 2883).Results. Сonsecutive vaccination with pneumococcal conjugate and polysaccharide vaccines leads to decreased isolation rate of pneuniococcus from the sputum of CODP patients. The frequency of exacerbations, the need for antibiotic chemotherapy and hospitalizations also goes down.

Cutting Time and Regrowth Age Affect the Quality of Elephant Grass Silage

The objective of this study was to evaluate the effects of regrowth age (RA) and cutting time (CT) of elephant grass (Cenchrus purpureus cv. Cameroon) on the fermentation profile, microorganism population, and nutritive value of the silage in two simultaneous trials at different sites. A 2 × 2 factorial scheme with two CTs (08:00 and 14:00) and two RAs (8 and 16 weeks) at ensilage was used in a completely randomized design, with four replicates in each trial, totaling 16 experimental units per trial. Results showed that ammonia nitrogen to total nitrogen content (N-NH3/TN) ranged from 71.8 (14:00; 16 weeks) to 137.0 g kg -1 (14:00; 8 weeks). Elephant grass silage harvested at 14:00 at 8 weeks had the lowest pH (3.53) and highest lactic acid content (39.7 g kg-1 dry matter). The in vitro dry matter digestibility (IVDMD) was higher (P < 0.05) in the silage of plants harvested at 8 weeks than in the silage harvested at 16 weeks (59.9 vs. 46.8%, respectively). In trial 2, elephant grass silage harvested at 14:00 had lower pH and acetic acid content. The IVDMD was higher in elephant grass silage harvested at 14:00, with values of 65.3% and 56.2% at 8 and 16 weeks, respectively. We recommend elephant grass harvested at 8 weeks of regrowth and cut at 14:00 to produce silage with better nutritive value and fermentative profile.

Biodegradable Antimicrobial Films for Food Packaging: Effect of Antimicrobials on Degradation

The environmental problem generated by the massive consumption of plastics makes necessary the developing of biodegradable antimicrobial materials that can extend food shelf-life without having a negative impact on the environment. The current situation regarding the availability of biodegradable food packaging materials has been analysed, as well as different studies where antimicrobial compounds have been incorporated into the polymer matrix to control the growth of pathogenic or spoilage bacteria. Thus, the antimicrobial activity of active films based on different biodegradable polymers and antimicrobial compounds has been discussed. Likewise, relevant information on biodegradation studies carried out with different biopolymers in different environments (compost, soil, aquatic), and the effect of some antimicrobials on this behavior, are reviewed. In most of the studies, no relevant effect of the incorporated antimicrobials on the degradation of the polymer were observed, but some antimicrobials can delay the process. The changes in biodegradation pattern due to the presence of the antimicrobial are attributed to its influence on the microorganism population responsible for the process. More studies are required to know the specific influence of the antimicrobial compounds on the biodegradation behavior of polymers in different environments. No studies have been carried out or marine media to this end.

Kinetic study of biogas production from anaerobic digestion of vinasse waste

Vinasse, a sugar-ethanol residue, is used as a substrate for biogas production. The characteristics of the vinasse wastewater used were 216,000 mg-COD/L, pH 4.1, and 68.42 mg/L volatile solids. The sludge/wastewater ratio was controlled at about 1.5−2.0, by weight. Biogas production enhancement was studied in relation to two parameters – Citadel BioCat + , a commercial biocatalyst containing a large microorganism population as the methanogenic bacteria source (5 and 10 g), and reaction temparature (30 and 37 °C). Biogas production kinetics were evaluated. The presence of the biocatalyst enhanced biogas production significantly, as well as reducing the time required for anaerobic digestion. The first-order kinetic model described the biodegradation process. The best results were found using 10 g of biocatalyst at 37 °C – i.e., the optimum results based on biogas production potential (A), the highest biogas production rate (U), the minimum biogas production time (λ), and kinetic organic biodegradability constants (k) of 102.71 mL/g-COD, 11.17 mL/g-COD/d, 0.95 day, and 0.0533 day − 1, respectively. COD removal efficiency was up to 60%.

Methodological approaches to evaluate dehydrogenase activity as a good indicator of soil functionality.

&lt;p&gt;Dehydrogenase activity (DHA) has been widely used as a good indicator to assess the oxidative status in soils. The common method determination relies on the reduction of an artificial electron receptor by the soil microorganisms, namely, a soluble tetrazolium salt that acquires a red color in its reduced form (formazan), being this way easily measured by colorimetry, after extraction by a proper solvent. This activity is very sensitive to all the factors that can reach the upper layer of soils, especially temperature and moisture, and its use has become very useful to determine the degree of xenobiotics toxicity or the goodness, or not, of agricultural procedures and management. To establish an appropriate methodology for the measurement and monitoring of this activity, in our work we evaluate the most relevant aspects that must be taken into account so that the determination of this activity is as consistent as possible.&lt;/p&gt;&lt;p&gt;Incubation time and pre-incubation: The incubation time appears as the main source of trouble in the interpretation of results. Most of the time, an incubation time of 24 hours is used, but some authors recommend shorter incubation periods to make the measurements at an initial rate and that way use a linear function. For this reason, some authors advise shorter periods of incubation after having a pre-incubation time with glucose or yeast extract. This way the reducing potential of the soil will be better represented.&lt;/p&gt;&lt;p&gt;Soil moisture: &amp;#160;For the DHA results of a certain area to be comparable, the degree of soil humidity has to be necessarily standardized since any change in soil moisture will lead to changes in DHA. Dry soils give figures of DHA close to zero. Precise readings of DHA can only be obtained minimizing the moisture interactions. A pre-incubation of 10 days with the soil hydrated with 50% of the water holding capacity, not only ensures equal moisture for all the samples but also serves to reactivate the soil microorganism population. After that, samples should be immediately incubated with the electron receptor and analyzed.&lt;/p&gt;&lt;p&gt;Formazan extraction: Special physicochemical properties of soils can lead to better or worse extraction of formazan. Some authors advise carrying out a simple trial to establish the degree of extraction of the formazan according to the slope of a linear function between the added formazan and that extracted.&lt;/p&gt;&lt;p&gt;Optimal TTC concentration: Some toxicity of TTC has been raised recently. Although the concentration of the substrate must be sufficient to saturate all the enzymatic capacity, it is advisable not to add an excess of TTC. The quantity and quality of organic matter may be behind the degree of severity of the toxic effect of TTC.&lt;/p&gt;

Microbiota of a UASB Reactor Treating Palm Oil Mill Effluent Using HiSeq Sequencing

Potential microbial communities in the UASB reactor fed with two different substrates i.e synthetic wastewater and raw palm oil mill effluent (POME) were elucidated by using one of the most popular techniques in molecular methods, viz 16S rDNA cloning. The methodology involved; the extraction of nucleic acids, amplification and cloning of the 16S rRNA genes on sequencing HiSeq platform and finally identification and affiliation of the isolated clone with the aid of phylogenetic software. Results showed that the genus methanosarcina and methanosaeta were dominant methanogens in this study for both substrates types. Overall, microbial population (Bacteria and Archaea) in sample A (POME as substrate) is more diverse compared to sample B (synthetic wastewater as substrate) due to abundance of microorganism population in raw POME which was used as a substrate. However for the methanogenic (Archaea) diversity in both samples, there was not much different between sample A and sample B probably due to similar inoculum was inoculated in the reactor despite of have using different substrate type.

Microorganism population, theobromine, antioxidant, and FTIR analysis of Samarinda cocoa bean fermented with Saccharomyces cerevisiae and Acetobacter aceti

This research aimed to observe S. cerevisiae and A. aceti induced fermentation of cocoa bean from Samarinda, Indonesia, in comparison to commercial cocoa bean in terms of microbial population, pH, total acids, total phenols, theobromine, antioxidant capacity, and FTIR profile. Cocoa beans were fermented with a boxed fermentation method resembling commercial plantation for four days at ambient box temperature (35-40°C). Four fermentation samples were produced which were spontaneous, 2% Saccharomyces cerevisiae, Acetobacter aceti, or mixed culture (S. cerevisiae and A. aceti) induced fermentations. Total Plate Count (TPC) and Total Yeast-Mold (TYM), pH, total phenol, theobromine, antioxidant activity, and FTIR analyses were performed according to the established method. There was no significant difference in the microbe population in all fermented cocoa. Mixed culture fermented cocoa had a slightly lower final pH. S. cerevisiae fermented cocoa produced the highest total phenol compared to the same compound content in other fermented cocoa. The mixed culture fermented cocoa had better theobromine content 162.3±22.6 ppm, antioxidant capacity 424.9±3.3 ppm, and the closest theobromine and caffeine identification zones to commercial cocoa samples. The use of mixed culture of S. cerevisiae and A. aceti is suggested as the better inoculum to ferment cocoa bean at local farms.