scholarly journals Evaluation of Feasibility of Using the Bacteriophage T4 Lysozyme to Improve the Hydrolysis and Biochemical Methane Potential of Secondary Sludge

Energies ◽  
2019 ◽  
Vol 12 (19) ◽  
pp. 3644
Author(s):  
Sangmin Kim ◽  
Seung-Gyun Woo ◽  
Joonyeob Lee ◽  
Dae-Hee Lee ◽  
Seokhwan Hwang
Keyword(s):  
Cell Wall ◽  
Bacterial Cell ◽  
Wastewater Treatment Plants ◽  
Biogas Production ◽  
Bacteriophage T4 ◽  
Suspended Solid ◽  
T4 Lysozyme ◽  
Biochemical Methane Potential ◽  
Secondary Sludge ◽  
Methane Potential

Anaerobic digestion (AD) of secondary sludge is a rate-limiting step due to the bacterial cell wall. In this study, experiments were performed to characterize secondary sludges from three wastewater treatment plants (WWTPs), and to investigate the feasibility of using bacteriophage lysozymes to speed up AD by accelerating the degradation of bacterial cell walls. Protein was the main organic material (67.7% of volatile solids in the sludge). The bacteriophage T4 lysozyme (T4L) was tested for hydrolysis and biochemical methane potential. Variations in the volatile suspended solid (VSS) concentration and biogas production were monitored. The VSS reduction efficiencies by hydrolysis using T4L for 72 h increased and ranged from 17.8% to 26.4%. Biogas production using T4L treated sludges increased and biogas production was increased by as much as 82.4%. Biogas production rate also increased, and the average reaction rate coefficient of first-order kinetics was 0.56 ± 0.02/d, which was up to 47.5% higher compared to the untreated samples at the maximum. Alphaproteobacteria, Betaproteobacteria, Flavobacteriia, Gammaproteobacteria, and Sphingobacteriia were major microbial classes in all sludges. The interpretation of the microbial community structure indicated that T4L treatment is likely to increase the rate of cell wall digestion.

scholarly journals Biochemical Methane Potential of Cork Boiling Wastewater at Different Inoculum to Substrate Ratios

2021 ◽  
Vol 11 (7) ◽  
pp. 3064
Author(s):  
Roberta Mota-Panizio ◽  
Manuel Jesús Hermoso-Orzáez ◽  
Luis Carmo-Calado ◽  
Gonçalo Lourinho ◽  
Paulo Sérgio Duque de Brito
Keyword(s):  
Anaerobic Digestion ◽  
Biogas Production ◽  
Treatment Plant ◽  
Organic Substrates ◽  
Biochemical Methane Potential ◽  
Volatile Solids ◽  
Working Volume ◽  
Methane Potential ◽  
Bmp Test ◽  
Cork Industry

The present study evaluates the digestion of cork boiling wastewater (CBW) through a biochemical methane potential (BMP) test. BMP assays were carried out with a working volume of 600 mL at a constant mesophilic temperature (35 °C). The experiment bottles contained CBW and inoculum (digested sludge from a wastewater treatment plant (WWTP)), with a ratio of inoculum/substrate (Ino/CBW) of 1:1 and 2:1 on the basis of volatile solids (VSs); the codigestion with food waste (FW) had a ratio of 2/0.7:0.3 (Ino/CBW:FW) and the codigestion with cow manure (CM) had a ratio of 2/0.5:0.5 (Ino/CBW:CM). Biogas and methane production was proportional to the inoculum substrate ratio (ISR) used. BMP tests have proved to be valuable for inferring the adequacy of anaerobic digestion to treat wastewater from the cork industry. The results indicate that the biomethane potential of CBWs for Ino/CBW ratios 1:1 and 2:1 is very low compared to other organic substrates. For the codigestion tests, the test with the Ino/CBW:CM ratio of 2/0.7:0.3 showed better biomethane yields, being in the expected values. This demonstrated that it is possible to perform the anaerobic digestion (AD) of CBW using a cosubstrate to increase biogas production and biomethane and to improve the quality of the final digestate.

scholarly journals Genetically Encoded Biosensor-Based Screening for Directed Bacteriophage T4 Lysozyme Evolution

2020 ◽  
Vol 21 (22) ◽  
pp. 8668
Author(s):  
Seung-Gyun Woo ◽  
Seong Keun Kim ◽  
Baek-Rock Oh ◽  
Seung-Goo Lee ◽  
Dae-Hee Lee
Keyword(s):  
High Throughput Screening ◽  
Bacteriophage T4 ◽  
T4 Lysozyme ◽  
Screening System ◽  
Random Mutation ◽  
Secondary Sludge ◽  
Enzyme Screening ◽  
Model Protein ◽  
Genetically Encoded Biosensor ◽  
Lysozyme Evolution

Lysozyme is widely used as a model protein in studies of structure–function relationships. Recently, lysozyme has gained attention for use in accelerating the degradation of secondary sludge, which mainly consists of bacteria. However, a high-throughput screening system for lysozyme engineering has not been reported. Here, we present a lysozyme screening system using a genetically encoded biosensor. We first cloned bacteriophage T4 lysozyme (T4L) into a plasmid under control of the araBAD promoter. The plasmid was expressed in Escherichia coli with no toxic effects on growth. Next, we observed that increased soluble T4L expression decreased the fluorescence produced by the genetic enzyme screening system. To investigate T4L evolution based on this finding, we generated a T4L random mutation library, which was screened using the genetic enzyme screening system. Finally, we identified two T4L variants showing 1.4-fold enhanced lytic activity compared to native T4L. To our knowledge, this is the first report describing the use of a genetically encoded biosensor to investigate bacteriophage T4L evolution. Our approach can be used to investigate the evolution of other lysozymes, which will expand the applications of lysozyme.

scholarly journals Co-Digestion of Extended Aeration Sewage Sludge with Whey, Grease and Septage: Experimental and Modeling Determination

2021 ◽  
Vol 13 (16) ◽  
pp. 9199
Author(s):  
Gérard Merlin ◽  
Jonathan Outin ◽  
Hervé Boileau
Keyword(s):  
Biogas Production ◽  
Mechanistic Model ◽  
Treatment Plant ◽  
Second Step ◽  
Stirred Tank Reactors ◽  
Positive Effects ◽  
Secondary Sludge ◽  
Negative Effect ◽  
Methane Potential ◽  
Continuous Stirred Tank

The potential of co-digestion mixing thickened secondary sludge (TS) from extended aeration wastewater treatment plant and locally available substrates (whey, grease and septage) has been studied in this work, using three steps. The first step was a batch test to determine the biological methane potential (BMP) of different mixtures of the three co-substrates with TS. The second step was carried out with lab-scale reactors (20 L), simulating anaerobic continuous stirred tank reactors, fed by three mixtures of co-substrates that were determined according to the previous step results. Modeling was applied in the third step, using ADM1 as a mechanistic model to help understand the co-digestion process. According to the BMP step, septage used as a co-substrate has a negative effect on performance, and the addition of 10–30% grease or whey would lead to a gain of around 60–70% in the production of methane. The results from the reactor tests did not validate the positive effects observed with the BMP assay but confirmed good biodegradation efficiency (> 85%). The main purpose of co-digestion in this scenario is to recover energy from waste and effluents that would require even more energy for their treatment. The protein and lipid percentages of particulate biodegradable COD are important variables for digester stability and methane production, as predicted by modeling. The results of simulations with the ADM1 model, adapted to co-digestion, confirmed that this model is a powerful tool to optimize the process of biogas production.

scholarly journals Biogas Production from Physicochemically Pretreated Grass Lawn Waste: Comparison of Different Process Schemes

Molecules ◽  
2020 ◽  
Vol 25 (2) ◽  
pp. 296 ◽  
Author(s):  
Georgia Antonopoulou ◽  
Dimitrios Vayenas ◽  
Gerasimos Lyberatos
Keyword(s):  
Biogas Production ◽  
Economic Assessment ◽  
Methane Yield ◽  
Biochemical Methane Potential ◽  
Naoh Pretreatment ◽  
Volatile Solids ◽  
Methane Potential ◽  
Whole Slurry ◽  
Almost All ◽  
Pretreated Biomass

Various pretreatment methods, such as thermal, alkaline and acid, were applied on grass lawn (GL) waste and the effect of each pretreatment method on the Biochemical Methane Potential was evaluated for two options, namely using the whole slurry resulting from pretreatment or the separate solid and liquid fractions obtained. In addition, the effect of each pretreatment on carbohydrate solubilization and lignocellulossic content fractionation (to cellulose, hemicellulose, lignin) was also evaluated. The experimental results showed that the methane yield was enhanced with alkaline pretreatment and, the higher the NaOH concentration (20 g/100 gTotal Solids (TS)), the higher was the methane yield observed (427.07 L CH4/kg Volatile Solids (VS), which was almost 25.7% higher than the BMP of the untreated GL). Comparing the BMP obtained under the two options, i.e., that of the whole pretreatment slurry with the sum of the BMPs of both fractions, it was found that direct anaerobic digestion without separation of the pretreated biomass was favored, in almost all cases. A preliminary energy balance and economic assessment indicated that the process could be sustainable, leading to a positive net heat energy only when using a more concentrated pretreated slurry (i.e., 20% organic loading), or when applying NaOH pretreatment at a lower chemical loading.

scholarly journals Chemical pre-treatments on oil palm empty fruit bunches: Impacts on characteristics and methane potential

2021 ◽  
Vol 924 (1) ◽  
pp. 012071
Author(s):  
N A Rohma ◽  
S Suhartini ◽  
I Nurika
Keyword(s):  
Lignocellulosic Biomass ◽  
Oil Palm ◽  
Biogas Production ◽  
Lignin Content ◽  
Test System ◽  
Biochemical Methane Potential ◽  
Empty Fruit Bunches ◽  
Methane Potential ◽  
Pre Treatment ◽  
Bmp Test

Abstract Production of biogas from lignocellulosic biomass by anaerobic digestion (AD) has attracted much interest. Oil palm empty fruit bunches (OPEFB), one of lignocellulosic biomass, is highly abundant in Indonesia and has potential as feedstock for bioenergy production such as biogas or methane. Yet, pre-treatments are needed to improve biogas production due to its complex crystalline structures. Chemical pre-treatments with acid or alkaline solution were reported to increase cellulose or highly reduce the lignin content of OPEFB. This study aimed to evaluate the effect of acid and alkaline pre-treatments on the characteristics of OPEFB and methane potential. The acid pre-treatment experimental design was used factor of H2SO4 concentration (1, 1.3, and 1.6 (%v/v)) and NaOH concentration (1.8, 2.8, and 3.8 (%w/v)). Methane potential evaluation was carried out using the biochemical methane potential (BMP) test with the Automatic Methane Potential Test System (AMPTS) II under mesophilic condition (37°C), operated for 28 days. The results showed that both dilute acid and alkaline pre-treatment positively impact altering the characteristics of OPEFB, hence the specific methane potential. Alkaline pre-treatment with NaOH 3.8 (%w/v) gave the highest average SMP value of 0.161 ± 0.005 m3 CH4/kgVSadded.

Influence of lignin on biochemical methane potential of biomass for biogas production

2011 ◽  
Vol 22 ◽  
pp. S146
Author(s):  
Jin M Triolo ◽  
Sven G Sommer ◽  
Henrik B Moller ◽  
Martin R Weisbjerg ◽  
Xinyuan Jiang
Keyword(s):  
Biogas Production ◽  
Biochemical Methane Potential ◽  
Methane Potential

scholarly journals Optimisation of C:N Ratio for Co-Digested Processed Industrial Food Waste and Sewage Sludge Using the BMP Test

2011 ◽  
Vol 9 (1) ◽  
Author(s):  
Zuhaib Siddiqui ◽  
N.J. Horan ◽  
Kofi Anaman
Keyword(s):  
Sewage Sludge ◽  
Food Waste ◽  
Biogas Production ◽  
C:N Ratio ◽  
Methane Yield ◽  
Biochemical Methane Potential ◽  
Volatile Solids ◽  
Methane Potential ◽  
Biomethane Production ◽  
Bmp Test

Biomethane production from processed industrial food waste (IFW) in admixture with sewage sludge (primary and waste activated sludge: PS and WAS) was evaluated at a range of C:N ratios using a standard biochemical methane potential (BMP) test. IFW alone had a C:N of 30 whereas for WAS it was 5.4 and thus the C:N ratio of the blends fell in that range. Increasing the IFW content in mix improves the methane potential by increasing both the cumulative biogas production and the rate of methane production. Optimum methane yield 239 mL/g VSremoved occurred at a C:N ratio of 15 which was achieved with a blend containing 11 percent (w/w) IFW. As the fraction of IFW in the blend increased, volatile solids (VS) destruction was increased and this led to a reduction in methane yield and amount of production. The highest destruction of volatile solids of 93 percent was achieved at C:N of 20 followed by C:N 30 and 15. A shortened BMP test is adequate for evaluating optimum admixtures.

scholarly journals Influence of conditioning agents and enzymic hydrolysis on the biochemical methane potential of sewage sludge

2013 ◽  
Vol 68 (7) ◽  
pp. 1622-1632 ◽  
Author(s):  
Elena Marañón ◽  
Luis Negral ◽  
Yolanda Fernández-Nava ◽  
Leonor Castrillón
Keyword(s):  
Sewage Sludge ◽  
Methane Production ◽  
Wastewater Treatment Plants ◽  
Solid Phase ◽  
Enzymic Hydrolysis ◽  
Biochemical Methane Potential ◽  
General Improvement ◽  
Methane Potential ◽  
Pre Treatment ◽  
Cationic Polyelectrolytes

Biochemical methane potential (BMP) tests have been carried out on sewage sludge from two wastewater treatment plants to assess the effect of additives (FeCl3 and two cationic polyelectrolytes) used in sludge dewatering. BMP tests were also carried out on the concentrated solid phase from the enzymic hydrolysis pre-treatment (42 °C, 48 h). FeCl3 had no significant effect on specific methane production, obtaining 242–246 LCH4/kgVSo. The effect of the combination of polyelectrolyte and FeCl3 depended on the polyelectrolyte and the sludge, but generally led to an increase in specific methane production (25–40%). When enzymic hydrolysis was applied as a pre-treatment, specific methane production increased from 6.8% in the sludge containing FeCl3 to 20% in the sludge without FeCl3, although the increases were not statistically significant. In terms of LCH4/kgVSrem, a general improvement was achieved both by means of additives and by enzymic hydrolysis. However, this improvement was only significant in the case of sludge which had undergone previous enzymic hydrolysis (62%) and in the untreated sludge containing a polyelectrolyte and FeCl3 (24%). Cationic polyelectrolytes inhibited solid–liquid separation during enzymic hydrolysis and, although the presence of only FeCl3 did not affect this separation, a significant decrease (32%) in LCH4/kgVSrem was observed.

Mesophilic Fermentation of SOMW in a Micro Pilot-Scale Anaerobic Digester

2013 ◽  
Vol 827 ◽  
pp. 84-90 ◽  
Author(s):  
Maurizio Carlini ◽  
Sonia Castellucci ◽  
Silvia Cocchi
Keyword(s):  
Anaerobic Digestion ◽  
Energy Production ◽  
Biogas Production ◽  
Ph Control ◽  
Pilot Scale ◽  
Biochemical Methane Potential ◽  
Mediterranean Countries ◽  
Methane Potential ◽  
Environmentally Sound ◽  
Bmp Test

One of the most promising processes to exploit Solid Olive-Mill Waste (SOMW) for energy production is anaerobic digestion. An experimental study has been carried out on SOMW and inoculum, consisting of Cattle Slurry Digested (CSD) and coming from an anaerobic digestion plant. A substrate with an optimal supply ratio equal to 2:1 has been investigated in a reactor at 37°C by analysing the biogas production. The Biochemical Methane Potential (BMP) test has been carried out, monitoring pH, biogas production (amount and composition). According to the tests results, SOMWs needed to be diluted and inoculated, moreover the pH control is foundamental in order to obtain a significant biogas production. Anaerobic digestion plant of SOMW should be promoted in Mediterranean countries as an environmentally sound option for waste management and energy production, since olive mills are very widespread agro-industries in this area.

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