Effect of operational pH on biohydrogen production from food waste using anaerobic batch reactors

2014 ◽  
Vol 69 (9) ◽  
pp. 1886-1893 ◽  
Author(s):  
Chaeyoung Lee ◽  
Sewook Lee ◽  
Sun-Kee Han ◽  
Sunjin Hwang
Keyword(s):  
Food Waste ◽  
Fish Analysis ◽  
Batch Reactors ◽  
Clostridium Species ◽  
Ph Values ◽  
Species Cluster ◽  
Initial Ph ◽  
H2 Yield ◽  
Total Bacteria

This study was performed to investigate the influence of operational pH on dark H2 fermentation of food waste by employing anaerobic batch reactors. The highest maximum H2 yield was 1.63 mol H2/mol hexoseadded at operational pH 5.3, whereas the lowest maximum H2 yield was 0.88 mol H2/mol hexoseadded at operational pH 7.0. With decreasing operational pH values, the n-butyrate concentration tended to increase and the acetate concentration tended to decrease. The highest hydrogen conversion efficiency of 11.3% was obtained at operational pH 5.3, which was higher than that (8.3%) reported by a previous study (Kim et al. (2011) ‘Effect of initial pH independent of operational pH on hydrogen fermentation of food waste’, Bioresource Technology 102 (18), 8646–8652). The new result indicates that the dark fermentation of food waste was stable and efficient in this study. Fluorescence in situ hybridization (FISH) analysis showed that Clostridium species Cluster I accounted for 84.7 and 13.3% of total bacteria at operational pH 5.3 and pH 7.0, respectively, after 48 h operation.

scholarly journals Population Structure and Morphotype Analysis of “CandidatusAccumulibacter” Using FluorescenceIn SituHybridization-Staining-Flow Cytometry

2019 ◽  
Vol 85 (9) ◽  
Author(s):  
Chao Li ◽  
Wei Zeng ◽  
Ning Li ◽  
Yu Guo ◽  
Yongzhen Peng
Keyword(s):  
Flow Cytometry ◽  
Population Structure ◽  
Electron Acceptor ◽  
Phosphorus Removal ◽  
Fish Analysis ◽  
Bacterial Cells ◽  
Denitrifying Phosphorus Removal ◽  
Optimal Method ◽  
Total Bacteria

ABSTRACT“CandidatusAccumulibacter” is the dominant polyphosphate-accumulating organism (PAO) in denitrifying phosphorus removal (DPR) systems. In order to investigate the community structure and clade morphotypes of “CandidatusAccumulibacter” in DPR systems through flow cytometry (FCM), denitrifying phosphorus removal of almost 100% using nitrite and nitrate as the electron acceptor was achieved in sequencing batch reactors (SBRs). An optimal method of flow cytometry combined with fluorescencein situhybridization and SYBR green I staining (FISH-staining-flow cytometry) was developed to quantify PAOs in DPR systems. By setting the width value of FCM, bacterial cells in a sludge sample were divided into three groups in different morphotypes, namely, coccus, coccobacillus, and bacillus. Average percentages that the three different PAO populations accounted for among total bacteria from SBR1 (SBR2) were 42% (45%), 14% (13%), and 4% (2%). FCM showed that the ratios of PAOs to total bacteria in the two reactors were 61% and 59%, and the quantitative PCR (qPCR) results indicated that IIC was the dominant “CandidatusAccumulibacter” clade in both denitrifying phosphorus removal systems, reaching 50% of the total “CandidatusAccumulibacter” bacteria. The subdominant clade in the reactor with nitrite as the electron acceptor was IID, accounting for 31% of the total “CandidatusAccumulibacter” bacteria. The FCM and qPCR results suggested that clades IIC and IID were both coccus, clade IIF was coccobacillus, and clade IA was bacillus. FISH analysis also indicated that PAOs were major cocci in the systems. An equivalence test of FCM-based quantification confirmed the accuracy of FISH-staining-flow cytometry, which can meet the quantitative requirements for PAOs in complex activated sludge samples.IMPORTANCEAs one group of the most important functional phosphorus removal organisms, “CandidatusAccumulibacter,” affiliated with theRhodocyclusgroup of theBetaproteobacteria, is a widely recognized and studied PAO in the field of biological wastewater treatment. The morphotypes and population structure of clade-level “CandidatusAccumulibacter” were studied through novel FISH-staining-flow cytometry, which involved denitrifying phosphorus removal (DPR) achieving carbon and energy savings and simultaneous removal of N and P, thus inferring the different denitrifying phosphorus removal abilities of these clades. Additionally, based on this method,in situquantification for specific polyphosphate-accumulating organisms (PAOs) enables a more efficient process and more accurate result. The establishment of FISH-staining-flow cytometry makes cell sorting of clade-level noncultivated organisms available.

scholarly journals Impact of pH on Lactate Formation and Utilization by Human Fecal Microbial Communities

2007 ◽  
Vol 73 (20) ◽  
pp. 6526-6533 ◽  
Author(s):  
Alvaro Belenguer ◽  
Sylvia H. Duncan ◽  
Grietje Holtrop ◽  
Susan E. Anderson ◽  
Gerald E. Lobley ◽  
...  
Keyword(s):  
Lactate Production ◽  
Lactate Accumulation ◽  
Ph Values ◽  
Human Intestinal Microbiota ◽  
Initial Ph ◽  
Stool Samples ◽  
Lactate Formation ◽  
Acrylate Pathway ◽  
Predominant Product

ABSTRACT The human intestine harbors both lactate-producing and lactate-utilizing bacteria. Lactate is normally present at <3 mmol liter−1 in stool samples from healthy adults, but concentrations up to 100 mmol liter−1 have been reported in gut disorders such as ulcerative colitis. The effect of different initial pH values (5.2, 5.9, and 6.4) upon lactate metabolism was studied with fecal inocula from healthy volunteers, in incubations performed with the addition of dl-lactate, a mixture of polysaccharides (mainly starch), or both. Propionate and butyrate formation occurred at pH 6.4; both were curtailed at pH 5.2, while propionate but not butyrate formation was inhibited at pH 5.9. With the polysaccharide mix, lactate accumulation occurred only at pH 5.2, but lactate production, estimated using l-[U-13C]lactate, occurred at all three pH values. Lactate was completely utilized within 24 h at pH 5.9 and 6.4 but not at pH 5.2. At pH 5.9, more butyrate than propionate was formed from l-[U-13C]lactate in the presence of polysaccharides, but propionate, formed mostly by the acrylate pathway, was the predominant product with lactate alone. Fluorescent in situ hybridization demonstrated that populations of Bifidobacterium spp., major lactate producers, increased approximately 10-fold in incubations with polysaccharides. Populations of Eubacterium hallii, a lactate-utilizing butyrate-producing bacterium, increased 100-fold at pH 5.9 and 6.4. These experiments suggest that lactate is rapidly converted to acetate, butyrate, and propionate by the human intestinal microbiota at pH values as low as 5.9, but at pH 5.2 reduced utilization occurs while production is maintained, resulting in lactate accumulation.

Microbial community analysis involved in the aerobic/extended-idle process performing biological phosphorus removal

2013 ◽  
Vol 67 (3) ◽  
pp. 485-493 ◽  
Author(s):  
Tian-jing Zeng ◽  
Guo-jing Yang ◽  
Dong-bo Wang ◽  
Xiao-ming Li ◽  
Wei Zheng ◽  
...  
Keyword(s):  
Phosphorus Removal ◽  
Community Analysis ◽  
Microbial Community Analysis ◽  
Fish Analysis ◽  
Biological Phosphorus Removal ◽  
Acclimation Period ◽  
Polyphosphate Accumulating Organisms ◽  
Biological Phosphorus ◽  
Total Bacteria

Recently, it has been found that biological phosphorus removal can be achieved in an aerobic/extended-idle (AEI) process using both glucose and acetate as the sole substrate. However, the microbial consortiums involved in glucose-fed and acetate-fed systems have not yet been characterized. Thus the aims of this paper were to investigate the diversities and dynamics of bacterial communities during the acclimation period, and to quantify polyphosphate-accumulating organisms (PAOs) and glycogen-accumulating organisms (GAOs) in the systems. The phylogenetic analysis showed that the microbial communities were mainly composed of phylum Proteobacteria, Bacteroidetes, Chlorobi and another six kinds of unclassified bacteria. Fluorescence in-situ hybridization (FISH) analysis revealed that PAOs and GAOs accounted for 43 ± 7 and 16 ± 3% of all bacteria in the glucose-fed system, and 19 ± 4 and 35 ± 5% of total bacteria in the acetate-fed system, respectively. The results showed that the conventional PAOs could thrive in the AEI process, and a defined anaerobic zone was not necessarily required for putative PAOs growth.

scholarly journals Jacobsen syndrome and neonatal bleeding: report on two unrelated patients

2021 ◽  
Vol 47 (1) ◽  
Author(s):  
Gregorio Serra ◽  
Luigi Memo ◽  
Vincenzo Antona ◽  
Giovanni Corsello ◽  
Valentina Favero ◽  
...  
Keyword(s):  
Developmental Delay ◽  
De Novo ◽  
Comparative Genomic ◽  
Fish Analysis ◽  
Variable Degree ◽  
Jacobsen Syndrome ◽  
Contiguous Gene ◽  
Clinical Consequences ◽  
11Q Deletion

Abstract Introduction In 1973, Petrea Jacobsen described the first patient showing dysmorphic features, developmental delay and congenital heart disease (atrial and ventricular septal defect) associated to a 11q deletion, inherited from the father. Since then, more than 200 patients have been reported, and the chromosomal critical region responsible for this contiguous gene disorder has been identified. Patients’ presentation We report on two unrelated newborns observed in Italy affected by Jacobsen syndrome (JBS, also known as 11q23 deletion). Both patients presented prenatal and postnatal bleeding, growth and developmental delay, craniofacial dysmorphisms, multiple congenital anomalies, and pancytopenia of variable degree. Array comparative genomic hybridization (aCGH) identified a terminal deletion at 11q24.1-q25 of 12.5 Mb and 11 Mb, in Patient 1 and 2, respectively. Fluorescent in situ hybridization (FISH) analysis of the parents documented a de novo origin of the deletion for Patient 1; parents of Patient 2 refused further genetic investigations. Conclusions Present newborns show the full phenotype of JBS including thrombocytopenia, according to their wide 11q deletion size. Bleeding was particularly severe in one of them, leading to a cerebral hemorrhage. Our report highlights the relevance of early diagnosis, genetic counselling and careful management and follow-up of JBS patients, which may avoid severe clinical consequences and lower the mortality risk. It may provide further insights and a better characterization of JBS, suggesting new elements of the genotype-phenotype correlations.

Fluorescent in situ hybridization (FISH): A useful diagnostic tool for childhood conjunctival melanoma

2021 ◽  
pp. 112067212110307
Author(s):  
Raquel María Moral ◽  
Carlos Monteagudo ◽  
Javier Muriel ◽  
Lucía Moreno ◽  
Ana María Peiró
Keyword(s):  
In Situ Hybridization ◽  
Fluorescent In Situ Hybridization ◽  
Pediatric Population ◽  
Diagnostic Technique ◽  
Histopathological Diagnosis ◽  
Fish Analysis ◽  
Conjunctival Melanoma ◽  
Adequate Treatment ◽  
First Case

Introduction: Conjunctival melanoma is extremely rare in children and has low rates of resolution. Definitive histopathological diagnosis based exclusively on microscopic findings is sometimes difficult. Thus, early diagnosis and adequate treatment are essential to improve clinical outcomes. Clinical case: We present the first case in which the fluorescent in situ hybridization (FISH) diagnostic technique was applied to a 10-year-old boy initially suspected of having amelanotic nevi in his right eye. Based on the 65% of tumor cells with 11q13 (CCND1) copy number gain and 33% with 6p25 (RREB1) gain as measured by the FISH analysis, and on supporting histopathological findings, the diagnosis of conjunctival melanoma could be made. Following a larger re-excision, adjuvant therapy with Mitomycin C (MMC), cryotherapy and an amniotic membrane graft, the patient has remained disease-free during 9 years of long-term follow-up. Case discussion: Every ophthalmologist should remember to consider and not forget the possibility of using FISH analyses during the differential diagnosis of any suspicious conjunctival lesions. Genetic techniques, such as FISH, have led to great advances in the classification of ambiguous lesions. Evidence-based guidelines for diagnosing conjunctival melanoma in the pediatric population are needed to determine the most appropriate strategy for this age group.

scholarly journals Application of Furcellaran Nanocomposite Film as Packaging of Cheese

Polymers ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1428
Author(s):  
Agnieszka Pluta-Kubica ◽  
Ewelina Jamróz ◽  
Gohar Khachatryan ◽  
Adam Florkiewicz ◽  
Pavel Kopel
Keyword(s):  
Silver Nanoparticles ◽  
Nanocomposite Film ◽  
Microbiological Quality ◽  
Inhibitory Effect ◽  
Quality Properties ◽  
In Situ Method ◽  
And Migration ◽  
Total Bacteria

There is a serious need to develop and test new biodegradable packaging which could at least partially replace petroleum-based materials. Therefore, the objective of this work was to examine the influence of the recently developed furcellaran nanocomposite film with silver nanoparticles (obtained by an in situ method) on the quality properties of two cheese varieties: a rennet-curd (gouda) and an acid-curd (quark) cheese. The water content, physicochemical properties, microbiological and organoleptic quality of cheese, and migration of silver nanoparticles were examined. Both the number of Lactococcus and total bacteria count did not differ during storage of gouda regardless of the packaging applied. The number of Lactococcus decreased in analogous quark samples. The use of the film slowed down and inhibited the growth of yeast in gouda and quark, respectively. An inhibitory effect of this film on mold count was also observed; however, only regarding gouda. The level of silver migration was found to be lower in quark than in gouda. The film improved the microbiological quality of cheeses during storage. Consequently, it is worth continuing research for the improvement of this film in order to enable its use in everyday life.

scholarly journals Development of antibacterial and UV protective cotton fabrics using plant food waste and alien invasive plant extracts as reducing agents for the in-situ synthesis of silver nanoparticles

Cellulose ◽  
2021 ◽  
Author(s):  
Nina Čuk ◽  
Martin Šala ◽  
Marija Gorjanc
Keyword(s):  
Silver Nanoparticles ◽  
Green Tea ◽  
Food Waste ◽  
Cotton Fabrics ◽  
Reducing Agent ◽  
Plant Food ◽  
Japanese Knotweed ◽  
Tea Leaves ◽  
Green Tea Leaves

Abstract The development of cellulose-based textiles that are functionalised with silver nanoparticles (AgNP), synthesised according to a green approach, and offer protection against ultraviolet (UV) radiation and pathogenic bacteria is very important today. In the present work we demonstrate the environmentally friendly approach to obtain such textile material by AgNP synthesis directly (in-situ) on cotton fabrics, using water extracts of plant food waste (green tea leaves, avocado seed and pomegranate peel) and alien invasive plants (Japanese knotweed rhizome, goldenrod flowers and staghorn sumac fruit) as reducing agents. The extracts were analysed for their total content of phenols and flavonoids and their antioxidant activity. The synthesised AgNP on cotton were round, of different size and amount depending on the reducing agent used. The highest amount of AgNP was found for samples where Japanese knotweed rhizome extract was used as reducing agent and the lowest where extracts of goldenrod flowers and green tea leaves were used. Regardless of the reducing agent used to form AgNP, all cotton samples showed excellent protection against E. coli and S. aureus bacteria and against UV radiation with UV protection factor values above 50. The best results for UV protection even after the twelve repetitive washing cycles were found for the sample functionalized with AgNP synthesised with an extract of the Japanese knotweed rhizome. Due to the presence of AgNP on cotton, the air permeability and thermal conductivity decreased. AgNP had no effect on the change in breaking strength or elongation of fabrics. Graphic abstract

scholarly journals Enhancing bioenergy production from food waste by in situ biomethanation: Effect of the hydrogen injection point

2021 ◽  
Author(s):  
Cynthia Kusin Okoro‐Shekwaga ◽  
Andrew Ross ◽  
Miller Alonso Camargo‐Valero
Keyword(s):  
Food Waste ◽  
Injection Point ◽  
Bioenergy Production

Enhanced in-situ biomethanation of food waste by sequential inoculum acclimation: Energy efficiency and carbon savings analysis

2021 ◽  
Vol 130 ◽  
pp. 12-22
Author(s):  
Cynthia Kusin Okoro-Shekwaga ◽  
Andrew Barry Ross ◽  
Miller Alonso Camargo-Valero
Keyword(s):  
Energy Efficiency ◽  
Food Waste

Laboratory Testing for HER2/neu in Breast Carcinoma: An Evolving Strategy to Predict Response to Targeted Therapy

2001 ◽  
Vol 8 (5) ◽  
pp. 415-418 ◽  
Author(s):  
Nils M. Diaz
Keyword(s):  
Targeted Therapy ◽  
Breast Carcinoma ◽  
Gene Amplification ◽  
Laboratory Testing ◽  
False Positives ◽  
Response To Therapy ◽  
Fish Analysis ◽  
Breast Carcinomas ◽  
Testing Strategies

Background Laboratory testing of HER2/neu in breast carcinoma has become vital to patient care following the approval of trastuzumab as the first therapy to target the HER2/neu oncoprotein. Initial clinical trials used immunohistochemistry (IHC) to test for HER2/neu overexpression in order to select patients for therapy. Fluorescence in situ hybridization (FISH), which tests for gene amplification, is more specific and sensitive than IHC when either assay is compared with HER2/neu overexpression as determined by Northern or Western blot analysis. Many weak overexpressors on IHC testing are not gene amplified on FISH analysis. Such weak overexpressors may be considered false-positives and raise the question of how best to test for HER2/neu. Methods The literature was surveyed regarding testing for HER2/neu overexpression in breast carcinomas and alternative testing strategies. Results False-positive results are a significant problem when IHC is exclusively used to test for HER2/neu overexpression. The false-positives are overwhelmingly confined to the group of 2+ positives and do not respond to targeted therapy. In contrast, concordance between IHC and FISH is high when immunostaining is interpreted as either negative or strongly positive (3+). Whereas some recent studies have suggested that FISH may better predict response to anti-HER2/neu therapy than IHC, others have indicated that IHC is as effective a predictor as FISH. IHC is less technically demanding and costly than FISH. Conclusions IHC analysis of HER2/neu in breast carcinoma is a useful predictor of response to therapy with trastuzumab when strongly positive. Negative immunostaining is highly concordant with a lack of gene amplification by FISH. Most weakly positive overexpressors are false-positives on testing with FISH. Thus, screening of breast carcinomas with IHC and confirmation of weakly positive IHC results by FISH is an effective evolving strategy for testing HER2/neu as a predictor of response to targeted therapy.

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