Population Dynamics Of Microorganisms Research Articles

Community Structure of Bacteria and Archaea Associated with Geotextile Filters in Anaerobic Bioreactor Landfills

Landfills are an example of an environment that contains highly complex communities of microorganisms. To evaluate the microbial community structure, four stainless steel pilot-scale bioreactor landfills with single- and double-layered geotextile fabric were used. Two reactors (R-1 and R-2) contained municipal solid waste (MSW) and sewage sludge, while the other two reactors (R-3 and R-4) contained only MSW. A single layer of geotextile fabric (R2GT3 and R3GT3) was inserted in the drainage layers of the two reactors (R-2 and R-3), while a double layer of geotextile fabric (R4GT2 and R4GT1) was inserted in one of the reactors (R-4). Scanning electron microscopy demonstrated that biomass developed on the geotextile fabrics after 540 days of bioreactor operation. The metagenomics analyses of the geotextile samples by 16S rRNA gene sequencing indicated that the geotextile bacterial communities were dominated by the phyla Firmicutes, Bacteroidetes, and Thermotogeae, while Proteobacteria were detected as the rarest bacterial phylum in all the geotextile samples. Treponema, Caldicoprobacter, and Clostridium were the most dominant anaerobic and fermentative bacterial genera associated with the geotextile fabric in the bioreactors. Euryarchaeota was the predominant archaean phylum detected in all the geotextile samples. In the archaeal communities, Methanosarcina, and Vadin CA11 were identified as the predominant genera. The diversity of microorganisms in landfill bioreactors is addressed to reveal opportunities for landfill process modifications and associated operational optimization. Thus, this study provides insights into the population dynamics of microorganisms in geotextile fabrics used in bioreactor landfills.

Correlation between physico-chemical parameters with soil of Citrus rhizosphere microbes

The population dynamics of microorganisms in soil are extremely difficult to assess due to the complex nature of the soil environment. The diverse nutritional requirements of microorganisms in soil may not be easily estimated; hence, isolation of the soil microorganisms and studying them in the laboratory, as pure or mixed culture cannot be easily attained. The growth and colonization of soil microorganisms can be influenced by chemical, physical and biological properties of the soil. The availability of macro and micro nutrient element can limit microbial population growth in the particular soil ecosystem. Essential soil elements for plant growth such as nitrogen, phosphorous, sulfur and micronutrients influences the microbial population as these nutrient elements are also needed for microbial growth and activity. The prospect of manipulating crop rhizosphere microbial populations by inoculation of beneficial organisms i.e. Pseudomonas fluorescence and Trichoderma spp. and managing soil physico-chemical properties of soil, increases plant growth and control of many soil borne diseases has shown considerable promise in laboratory and field. Present investigation was carried out during 2014 - 2015 at Department of Plant Pathology, All India Co-ordinated Research Project on Fruits, Dr. P. D. K. V. Akola and Department of Soil Science and Agricultural Chemistry, Post Graduate Institute. Dr. Panjabrao Deshmukh Krishi Vidyapeeth, Akola (M.S.) by collecting soil samples from Akola (AK), Amravati (AM1 & AM2), Wardha(WR), Washim (WA), Yavatmal (YA), Nagpur (NA1&NA2) and Buldhana (BU) sampling site of Vidarbha region to know the correlation between physico-chemical parameters with soil rhizosphere microbes for which isolation of different microbes like bacteria, fungi was carried out. The result showed that in healthy rhizosphere, moisture, Organic carbon, Copper and Phosphorous are positively correlated with bacterial and fungal population whereas Temperature, Manganese, EC, Iron, Zinc, pH, and Potassium were negatively correlated. In diseased rhizosphere of citrus, Temperature, Manganese, Phosphorous, Nitrogen, Iron and Moisture were positively correlated whereas PH, Zn, Organic carbon and Potassium negatively correlated. The PCA analysis was carried out to see the influencing factor of Physio-chemical properties with microbial population at different locations. The result reported that the sampling sites Akola (AK) was influenced by Temperature, Moisture, Nitrogen, Copper and Zinc and Amravati (AM1) by Organic carbon, Moisture, Copper, Temperature, EC, Iron, Nitrogen, Potassium and Zinc. Whereas, Amravati (AM2) by Zinc, Nitrogen, Phosphorous, EC for microbial population in citrus rhizosphere ecosystem. In case of Wardha (WR) and Washim (WA), Temperature, Moisture, Nitrogen, Zinc, Iron, pH, are the most influencing factors whereas in Nagpur region NA1 and NA2, pH, Organic carbon, Moisture and Manganese are the factor which are responsible for the microbial population in the rhizosphere region of citrus. In Buldhana (BU) sampling sites, EC and Manganese whereas in Yavatmal (YA) sampling site pH, Iron and EC are the soil properties which influenced the microbial population in rhizosphere region of citrus.

Structure and function of microbial community involved in a novel full-scale prefix oxic coking wastewater treatment O/H/O system

A novel full-scale prefix oxic coking wastewater (CWW) biological treatment O/H/O system had been operated steadily six years with the effluent quality meeting national discharge standard. Comparing to the traditional CWW biological treatment process, which usually have an anaerobic unit at the start of the process, here the O/H/O system has obvious advantages in COD removal, total nitrogen removal and reduced energy consumption. It is very necessary to illustrate the structure and function of the microbial community involved in different bioreactors of the O/H/O system. High-throughput MiSeq sequencing was used to examine the 16S rRNA genes in this system. Results revealed a contrasting microbial composition among the activated sludge samples of three sequential bioreactors: the β-Proteobacteria related sequences dominated in the O1 activated sludge with the relative abundance of 56.44% while 7.53% of the sequences were assigned to Thiobacillus; Rhodoplanes related sequences dominated in the bioreactor H and O2 activated sludge with relative abundance of 8.86% and 8.92%, respectively. The physico-chemical characteristics of CWW were analyzed by standard methods and the operational parameters were routinely monitored to examine their effects on the microbial communities. The bioinformatics software package of phylogenetic investigation of communities by reconstruction of unobserved states (PICRUSt) was used to predict the microbial community functional profiling and found three dominant genera of Rhodoplanes, Lysobacter and Leucobacter enriched the xenobiotics biodegradation and metabolism pathway. The diverse and distinct microbial community involved in biological treatment processes of CWW treatment indicating that water characteristics and operational parameters determined the microbial community composition. These results significantly expanded our knowledge of the biodiversity and population dynamics of microorganisms and discerned the relationships between bacterial communities and environmental variables in the biological treatment processes. Moreover, in this study, we proposed a comprehensive biodegradation model of CWW treatment and defined as O/H/O system.

Impact of salinity on the population dynamics of microorganisms in a membrane bioreactor treating produced water

Biomass characteristics may change subject to a salinity increase when treating high strength wastewater. In this study, the impact of salinity in a membrane bioreactor (MBR) was investigated for the treatment of produced water (PW). MBR was operated as a pre-treatment prior to nanofiltration (NF) and reverse osmosis (RO). Mixed PW, that was originated from different oil, gas, and oil-gas wells, were subjected to pre-treatment for 146 days including three different operational phases: Low-salinity (~10 mS/cm), gradual increased salinity (10–40 mS/cm) and high salinity (~40 mS/cm). The results of this study showed that microorganisms could adapt using real wastewater and treat PW up to a certain level of the salinity. At high salinity levels of PW, the floc structure started to be disrupted and membrane fouling was accelerated. PCR-DGGE analysis confirmed the changes in microbial communities' composition in relation with high salinity. The results of the final treatment experiments presented that NF and RO treatment produced high-quality effluents that could be suitable for reuse.

A longitudinal analysis of methicillin-resistant and sensitive Staphylococcus aureus incidence in respect to specimen source, patient location, and temperature variation

Seasonal variations in temperature exert strong selective pressure on microorganism population dynamics and should be taken into account in epidemiological studies. The objective of the present study was to characterize the seasonal variation of staphylococcal infections in respect to patient location, specimen source, month of year, and temperature variation. A retrospective longitudinal time-series analysis of methicillin-resistant and methicillin-sensitive Staphylococcus aureus (MRSA and MSSA) was conducted in northeastern Ohio over a 5-year period. Multivariable time-series analyses were performed to detect the variations in the monthly incidence based on location of patients (inpatient, outpatient, and nursing homes), source of specimen (wound, respiratory tract, and urine), time of year (January-December), and temperature variation (average monthly over 5 years). The results indicated a gradual increase in both MRSA and MSSA infections, with outpatient cases representing the majority of cases. If present, the seasonal nature of MRSA infections varied based on specimen source and patient location, with wound infections from outpatients more prevalent in warmer months, and respiratory infections among inpatients more prevalent during colder months. The current report provides a longitudinal analysis of staphylococcal epidemiology, and in the process, identifies the seasonal nature of infections to be multifactorial, depending on such variables as specimen source and patient location. The seasonal nature of staphylococcal infections appears to be the product of a complex interaction among host, pathogen, and environment.

Bacterial population dynamics and sensorial quality loss in modified atmosphere packed fresh-cut iceberg lettuce

The end of shelf life of fresh-cut iceberg lettuce packed in modified atmosphere (MA) is determined by its visual quality and by its microbial load. The total microbial load should not exceed 6–7 log CFUg−1 mesophilic counting and be free of human pathogens. Not much is known about specific interactions between the levels of specific spoilage micro-organisms and the sensorial quality attributes of the fresh-cut product. We studied the changes in sensorial quality attributes and the growth and population dynamics of microorganisms in three independent batches of MA packed fresh-cut iceberg lettuce stored at 7°C.The sensorial quality of the fresh-cut product was daily evaluated by visual determination of color, shape (indication of crispness) and discoloration (browning); together these attributes were translated into an Overall Visual Quality (OVQ) value. In addition, off-odour and sourness production were scored immediately after opening of the bags. Samples of the fresh-cut product were taken to determine the total microbial load and to investigate the bacterial species composition using mass sequencing analysis.The decrease of OVQ over time showed a down sigmoid curve, reaching the limit of consumer acceptance after about eight days. Total bacterial counts increased from about 5 log at day 1 to about 8 log colony forming units (CFU) per gram at day 7. Initially, Pseudomonas species were dominant but when the package became anaerobic, lactic acid bacteria (LAB), in particular Leuconostoc spp. and Lactococcus spp. became more abundant and dominated the bacterial population. Especially the rapid growth of Leuconostoc species correlated with development of a sour off-odour, represented by the accumulation of acetic and lactic acids in the product and the decrease in OVQ. Results indicate that metabolites produced by LAB are responsible for off-odour production and loss of sensorial quality.Based on this knowledge, new strategies for shelf-life improvement may be designed to prevent the dominance of LAB in fresh cut lettuce or make shelf-life better predictable based on initial counts of LAB, that may assist the industry and retail to reduce food waste.

Population Dynamics of Microorganism and Greenhouse Gas Emission By Applying Chicken Manure in Peat Soil

<em>Peat land accumulates organic materials and emits greenhouse gas (GHG). Agricultural activities in peat land cause the subsidence of peat land surface and the loss of carbon in the form of GHG. Appropriate management of peat land for agriculture would reduce GHG emission. This research aims to understand the microorganism population dynamics and emission of GHG on the treatment of chicken manure application in peat land. The research was conducted in the GHG Laboratory of Indonesia Agricultural Environment Research Institute (IAERI) in 2012 using peat material taken from Jabiren, Central Kalimantan. The experiment was done by incubating peat soil for 2 months with the treatment of chicken manure application and without manure. The incubation experiment was conducted by using paralon PVC pipe. Parameters observed included pH, Eh, bacteria population and fungi, as well as GHG flux (CO<sub>2</sub>, CH<sub>4 </sub>and N<sub>2</sub>O). GHG samples taking method was used a sealed containment. The research result showed at the peat given chicken manure treatment, bacteria population decreased at the end of incubation; fungi population, however, increased. The application of chicken manure on peat land planted rubber trees and pineapples would reduce GHG emission by 12.8% as compared without manure application.</em>

Contrasting microbial community composition and function perspective in sections of a full-scale coking wastewater treatment system.

To characterize the microbial community of the coking wastewater (CWW) treatment system and to study the effects of CWW characteristics and operational parameters on microbial communities, active sludge samples were collected from a full-scale CWW treatment plant using three-phase fluidized bed biological reactors. High-throughput MiSeq sequencing was used to examine the 16S rRNA genes of microbiology, revealing a distinct microbial composition among the active sludge samples of three sequential bioreactors. Pseudomonas, Comamonas, and Thiobacillus-related sequences dominated in the anaerobic bioreactor A, aerobic bioreactor O1, and aerobic bioreactor O2 active sludge with relative abundance of 72.59, 56.75, and 27.82 %, respectively. The physico-chemical characteristics of CWW were analyzed by standard methods and operational parameters were recorded to examine their effects on the microbial communities. The redundancy analysis (RDA) results showed that the bacterial communities of bioreactors A, O1, and O2 correlated strongly with cyanides, phenols, and ammonia, respectively. These results expand the knowledge about the biodiversity and population dynamics of microorganisms and discerned the relationships between bacterial communities and environmental variables in the biological treatment processes in the full-scale CWW treatment system.

Effect of cadmium and zinc contamination on the population dynamics of soil microorgani

Changes in the population dynamics of microorganisms in a soil artificially contaminated with various doses of cadmium and zinc was examined from a quantitative point of view, under laboratory circumstances. The research was based on a chernozem soil originating from the area of a long-term microelement contamination model experiment (Nagyhörcsökpuszta, Hungary), which was carried out during 1991 in the Experimental Site of the Institute of Soil Science and Agricultural Chemistry, Centre for Agricultural Researche Hungarian Academy of Sciences, Budapest, Hungary. According to the amount of bacteria, microscopic fungi and nitrifying bacteria, it can be stated that the effect of contamination can be observed even in the perspective of nearly two decades. In more cases significant changes in the number of soil bacteria and microscopic fungi could be observed, and the nitrification activity increased in case of both microelements. Therefore the further research of changes in microbial activity of these soils can provide novel scientific results.

Study of resistance of modified wood to microbiological degradation

Identification of damage wood in building structures in the early stages , as well as predicting their development and forecasting, will assess the conditions and terms of use of the products, to determine the effectiveness of the methods and means of protection and make a decision about their improvement. The research and developed a mathematical model of the biological breakdown of the wood. According to the obtained dependence of the calculated population dynamics of microorganisms in the amount of plant material and the proportion of damaged material. The results of studies of biological wood failure rate of the incubation, including antiseptics modified and installed to reduce the influence of the modification speed and depth biodegradability.

Microorganisms in landfill bioreactors for accelerated stabilization of solid wastes

Landfill bioreactors (LBRs) with management of leachate and biogas have presented numerous advantages such as accelerated stabilization of solid wastes, reduced amount of leachate, and in situ leachate treatment. Such advantages have minimized environmental risks, have allowed extension of the useful life of the landfill site, and have fostered cost reduction. LBRs of three types have been developed using both anaerobic and aerobic modes: anaerobic, aerobic, and hybrid. Microorganisms in landfills cause various reactions related with organic fractions and heavy metals. Such functions have been stimulated in LBRs by recirculation of leachate with or without aeration. To date, most studies of microorganisms in LBRs have analyzed bacteria and archaea based on 16S rRNA genes and have analyzed fungi based on 18S rRNA genes from a taxonomical viewpoint. Indicator genes for specific functions in LBRs such as nitrification, denitrification, and methane production have also been monitored. The population dynamics of microorganisms in LBRs have been partially clarified, but the obtained data remain limited because of highly heterogeneous features of solid wastes inside LBRs. Systematic monitoring of microorganisms should be established to improve LBR performance.

Biodiversity and population dynamics of microorganisms in a full-scale membrane bioreactor for municipal wastewater treatment

The total, ammonia-oxidizing, and denitrifying Bacteria in a full-scale membrane bioreactor (MBR) were evaluated monthly for over one year. Microbial communities were analyzed by denaturing gradient gel electrophoresis (DGGE) and clone library analysis of the 16S rRNA and ammonia monooxygenase (amoA) and nitrous oxide reductase (nosZ) genes. The community fingerprints obtained were compared to those from a conventional activated sludge (CAS) process running in parallel treating the same domestic wastewater. Distinct DGGE profiles for all three molecular markers were observed between the two treatment systems, indicating the selection of specific bacterial populations by the contrasting environmental and operational conditions. Comparative 16S rRNA sequencing indicated a diverse bacterial community in the MBR, with phylotypes from the α- and β-Proteobacteria and Bacteroidetes dominating the gene library. The vast majority of sequences retrieved were not closely related to classified organisms or displayed relatively low levels of similarity with any known 16S rRNA gene sequences and thus represent organisms that constitute new taxa. Similarly, the majority of the recovered nosZ sequences were novel and only moderately related to known denitrifiers from the α- and β-Proteobacteria. In contrast, analysis of the amoA gene showed a remarkably simple ammonia-oxidizing community with the detected members almost exclusively affiliated with the Nitrosomonas oligotropha lineage. Major shifts in total bacteria and denitrifying community were detected and these were associated with change in the external carbon added for denitrification enhancement. In spite of this, the MBR was able to maintain a stable process performance during that period. These results significantly expand our knowledge of the biodiversity and population dynamics of microorganisms in MBRs for wastewater treatment.

Microbial population dynamics of inoculated low-grade chalcopyrite bioleaching columns

This study investigates the effect of temperature on the population dynamics of microorganisms in bioleaching columns charged with a low-grade chalcopyrite ore. A mixed culture containing ten known bioleaching microorganisms was used to inoculate four bioleaching columns operated at 60, 50, 40 or 30 °C. Subsequently, Terminal Restriction Fragment Length Polymorphism (T-RFLP) was used to examine the diversity of bacterial and archaeal populations in the leachates and ores of the four columns. Similar results from samples collected from different locations in the columns give confidence in the reproducibility of the methods used. Of the 10 microbial inoculants, only Acidithiobacillus caldus, Leptospirillum ferriphilum and Ferroplasma acidiphilum were identified from the leachate and the column solids. However, adventitious growth of a number of other species resulted in different microbial populations in the leachate and on the ore. The results bring into question the effectiveness of heap inoculation, a strategy proposed to overcome the paucity of thermophilic organisms occurring naturally, even in very long-term sulfide-leaching operations. The anticipated impact of temperature on the leachate population was ameliorated by the solution management regime used for the columns, which was chosen to imitate heap leach practice.

Effect of fermentation temperature on microbial population evolution using culture-independent and dependent techniques

Abstract The population dynamics of micro-organisms during grape-must fermentation has been thoroughly studied. However, the main approach has relied on microbiological methods based on plating. This approach may overlook micro-organisms that (i) grow slowly or do not grow well on artificial media or (ii) whose population size is small enough to be detected by regular sampling. Culture-independent methods have been used and compared with the traditional plating method during wine fermentations performed at two different temperatures (13 °C and 25 °C). These methods include a qualitative technique, the DGGE; a semi-quantitative technique, the direct cloning of amplified DNA; and a quantitative technique, the QPCR. The biodiversity observed in the must and at the beginning of fermentation was much higher when DGGE or direct cloning were used. Quantification of the most frequent non-Saccharomyces yeast, Hanseniaspora uvarum and Candida zemplinina, showed that they survived throughout the fermentation process and, specifically, it revealed the quantitatively relevant presence of C. zemplinina until the end of fermentation.

Nash Equilibria in Multi-Agent Motor Interactions

Social interactions in classic cognitive games like the ultimatum game or the prisoner's dilemma typically lead to Nash equilibria when multiple competitive decision makers with perfect knowledge select optimal strategies. However, in evolutionary game theory it has been shown that Nash equilibria can also arise as attractors in dynamical systems that can describe, for example, the population dynamics of microorganisms. Similar to such evolutionary dynamics, we find that Nash equilibria arise naturally in motor interactions in which players vie for control and try to minimize effort. When confronted with sensorimotor interaction tasks that correspond to the classical prisoner's dilemma and the rope-pulling game, two-player motor interactions led predominantly to Nash solutions. In contrast, when a single player took both roles, playing the sensorimotor game bimanually, cooperative solutions were found. Our methodology opens up a new avenue for the study of human motor interactions within a game theoretic framework, suggesting that the coupling of motor systems can lead to game theoretic solutions.

Environmental microbe and human pathogen: the ecology and microbiology of Vibrio cholerae

Vibrio cholerae, the bacterium that causes cholera, is a fascinating microorganism that occupies two distinct habitats: aquatic environments and human intestines. Although its activity in human hosts has received a great deal of attention because of its effect on human health, the microbe's behavior in natural ecosystems has received much less consideration. In this paper we briefly review the microbiology and ecology of V. cholerae, before highlighting four important areas for further research. First, V. cholerae acts as a typical heterotrophic bacterium while in aquatic environments, mineralizing organic matter for reuse within the food web. In addition, three key processes affect the microorganism's population dynamics and therefore its role in ecosystem processes: a viable-but-non-culturable (VBNC) state, attachment to environmental substrates, and bacterivory. Several factors link V. cholerae in its human and aquatic habitats, especially human activities that influence its growth conditions while out...

Environmental Microbe and Human Pathogen: The Ecology and Microbiology of Vibrio cholerae

Vibrio cholerae, the bacterium that causes cholera, is a fascinating microorganism that occupies two distinct habitats: aquatic environments and human intestines. Although its activity in human hosts has received a great deal of attention because of its effect on human health, the microbe's behavior in natural ecosystems has received much less consideration. In this paper we briefly review the microbiology and ecology of V. cholerae, before highlighting four important areas for further research. First, V. cholerae acts as a typical heterotrophic bacterium while in aquatic environments, mineralizing organic matter for reuse within the food web. In addition, three key processes affect the microorganism's population dynamics and therefore its role in ecosystem processes: a viable-but-non-culturable (VBNC) state, attachment to environmental substrates, and bacterivory. Several factors link V. cholerae in its human and aquatic habitats, especially human activities that influence its growth conditions while outside the body. These activities create feedbacks between humans and the environment that are at present not well understood, but which are likely to alter the persistence and spread of the resulting disease.

Effects of aphids and moth caterpillars on epiphytic microorganisms in canopies of forest trees

Different types of herbivores were investigated for their effects on microorganisms in the phyllosphere of forest trees during the growing season. Aphids on spruce, beech, and oak produced honeydew, which was readily consumed by microorganisms and resulted in two to three orders of magnitude higher densities (colony forming units) of bacteria, yeasts, and filamentous fungi on leaves of infested trees. The amounts of honeydew excreted by different aphid species and their mode of excretion (large droplets, tiny droplets scattered over leaves, production of wax wool) affected the degree to which honeydew could be processed by epiphytic microorganisms. All groups of microorganisms appeared to be energy limited. These results were consistent for different growth media offered to the microorganisms. Leaf-feeding moth caterpillars also positively affected the growth of microorganisms on leaves of beech and oak. The effects were more pronounced for bacteria and yeasts especially on oak. Thus, different functional groups of herbivores positively affected the growth of microorganisms in the phyllosphere of trees. It is suggested that the population dynamics of herbivores and their feeding characteristics are important features, which should be considered when the population dynamics of microorganisms in the canopies of trees is studied.

Mathematical model for soluble carbonaceous substrate biosorption

An activated sludge mathematical model for soluble carbonaceous substrate biosorption has been developed. The model allows the soluble COD fractions in biological reactors of a wastewater treatment plant and/or in batch cultivations to be predicted more precisely than by using conventional models. Special attention was paid to interactions between the biokinetic model structure and population dynamics of microorganisms in activated sludge. The model was developed using observations made on a synthetic wastewater which was dosed to a lab-scale, continuously operated plant with the D-R-D-N configuration. The development of the model advanced through several biokinetic models which resulted in a final version of the biosorption model. The model is constructed on a matrix structure. Adsorption, desorption and hydrolysis kinetics are incorporated into the model. Experimental results from batch cultivations carried out under anoxic and oxic conditions as well as some dynamic tests carried out with the continuously operated system served for the model calibration. Simulations of a wide diversity of kinetic tests demonstrate that the model is able to accurately predict the soluble COD under different cultivation conditions.

Mathematical model for soluble carbonaceous substrate biosorption

An activated sludge mathematical model for soluble carbonaceous substrate biosorption has been developed. The model allows the soluble COD fractions in biological reactors of a wastewater treatment plant and/or in batch cultivations to be predicted more precisely than by using conventional models. Special attention was paid to interactions between the biokinetic model structure and population dynamics of microorganisms in activated sludge. The model was developed using observations made on a synthetic wastewater which was dosed to a lab-scale, continuously operated plant with the D-R-D-N configuration. The development of the model advanced through several biokinetic models which resulted in a final version of the biosorption model. The model is constructed on a matrix structure. Adsorption, desorption and hydrolysis kinetics are incorporated into the model. Experimental results from batch cultivations carried out under anoxic and oxic conditions as well as some dynamic tests carried out with the continuously operated system served for the model calibration. Simulations of a wide diversity of kinetic tests demonstrate that the model is able to accurately predict the soluble COD under different cultivation conditions.