scholarly journals Biodiesel from wastewater: lipid production in high rate algal pond receiving disinfected effluent

2015 ◽  
Vol 71 (8) ◽  
pp. 1229-1234 ◽  
Author(s):  
Paula Peixoto Assemany ◽  
Maria Lucia Calijuri ◽  
Eduardo de Aguiar do Couto ◽  
Aníbal Fonseca Santiago ◽  
Alberto José Delgado dos Reis
Keyword(s):  
Lipid Content ◽  
Algal Biomass ◽  
Bacterial Load ◽  
Lipid Production ◽  
Biomass Concentration ◽  
Domestic Sewage ◽  
High Rate ◽  
Uv Disinfection ◽  
Potential Strategy ◽  
Micro Organisms

The production of different species of microalgae in consortium with other micro-organisms from wastewaters may represent an alternative process, to reduce the costs, for obtaining biofuels. The aim of this study was to evaluate the influence of pre-ultraviolet disinfection (UV) in the production of lipids from biomass produced in high rate ponds. Two high rate algal ponds were evaluated: a pond that received domestic sewage without disinfection and the other receiving domestic sewage previously disinfected by UV radiation (uvHRAP). The UV disinfection did not lead to significant differences in fatty acid profile and total lipid productivities, although it increased algal biomass concentration and productivity as well as lipid content. Moreover, the overall biomass concentrations and productivities decreased with the UV disinfection, mostly as a consequence of a loss in bacterial load. We thus conclude that uvHRAP disinfection may represent a potential strategy to promote the cleaner and safer growth of algal biomass when cultivated in consortium with other micro-organisms. Mainly regarding the use of wastewater as culture medium, together with a cheaper production of lipids for biodiesel, pre-disinfection may represent an advance since extraction costs could be significantly trimmed due to the increase in lipid content.

scholarly journals Characterization Chlorophytas microalgae with potential in the production of lipids for biofuels

2012 ◽  
Vol 5 (1) ◽  
pp. 93-102 ◽  
Author(s):  
Denis-Lorena Jaimes-Duarte ◽  
Wilder Soler-Mendoza ◽  
Josman Velasco-Mendoza ◽  
Yaneth Muñoz-Peñaloza ◽  
Néstor-Andrés Urbina-Suárez
Keyword(s):  
Biomass Production ◽  
Lipid Content ◽  
Lipid Production ◽  
Biomass Concentration ◽  
Production Yield ◽  
Selective Media ◽  
Media Control ◽  
Chlorella Sp ◽  
Nutritional Conditions ◽  
Potential Applications

This work is part of a megaproject that seeks to isolate microalgae of the Chlorophyta division native to Norte de Santander and identify their potential applications such as lipid production to be used as biofuel. Here we present the isolation of 11 microalgae strains from the Chlorophyta division found in two different wastewater environments. The collected strains were cultivated in selective media and purified through serial dilutions, depletion culture, and application of penicillin and gentamicin. Biomass production was evaluated and two strains were selected: CHL1 (Chlorella sp.) and DES1 (Desmodesmus sp.). The strains were cultivated on wastewater and PCG media (control), and their biomass concentration and lipid content were measured. Both strains reached similar biomass concentrations compared to their respective controls (CHL1 PCG 1.5 mg/L ± 0.035 mg/L, CHL1 AR 1.68 mg/L ± 0.036, DES1 PCG 1.66 mg/L ± 0.007, DES1 AR 2 mg/L ± 0.03) and their lipid content was slightly higher compared to their controls. The results show that the isolated and evaluated strains may have potential to be lipid producers, since their environmental and nutritional conditions have not been modified yet and adaptation may improve the production yield of lipids.

Algal production in wastewater treatment high rate algal ponds for potential biofuel use

2011 ◽  
Vol 63 (10) ◽  
pp. 2403-2410 ◽  
Author(s):  
J. B. K. Park ◽  
R. J. Craggs
Keyword(s):  
Wastewater Treatment ◽  
Biomass Production ◽  
Total Lipid ◽  
Lipid Content ◽  
Algal Biomass ◽  
Bacterial Biomass ◽  
Total Lipid Content ◽  
High Rate ◽  
Algal Production ◽  
Co2 Addition

Wastewater treatment High Rate Algal Ponds with CO2 addition could provide cost-effective and efficient tertiary-level wastewater treatment with the co-benefit of algal biomass production for biofuel use. Wastewater grown algal biomass can have a lipid content of 10–30% of dry weight, which could be used to make biodiesel. This research investigated algal biomass and total lipid production by two pilot-scale wastewater treatment HRAPs (4-day HRT) with and without CO2 addition under New Zealand mid summer (Nov–Jan) conditions. The influence of CO2 addition on wastewater treatment performance was also determined. CO2 was added to one of the HRAPs (the HRAPE) by maintaining the maximum pH of the pond below 8. Measurements of HRAP influent and effluent water qualities, total lipid content and algal biomass production were made twice a week over the experimental period. Both HRAPs achieved high levels of organic compound and nutrient removal, with >85% SBOD5, >92 NH4+-N and >70% DRP removal. Algal/bacterial biomass production in the HRAPE (15.2 g/m2/d) was improved by CO2 addition by ∼30% compared with that of the control HRAPW (10.6 g/m2/d). Total lipid content of the biomass grown on both HRAPs was slightly reduced (from 25% to 20%) with CO2 addition and the maximum total lipid content of ∼40% was observed in the HRAPW when low NH4+-N concentration (<0.5 mg/L) and high maximum pH (>10.0) occurred. Total lipid content of the biomass increased by ∼15% under nitrogen limiting conditions, however, overall algal/bacterial biomass production was reduced by half during the period of nitrogen limitation. More research is required to maintain algal production under near nitrogenlimiting conditions.

Culture Concordance in Different Sections of the Metatarsal Head: Interpretations of Microbiological Results

2021 ◽  
pp. 153473462110037
Author(s):  
Raul Juan Molines-Barroso ◽  
Esther García-Morales ◽  
David Sevillano-Fernández ◽  
Yolanda García-Álvarez ◽  
Francisco J. Álvaro-Afonso ◽  
...  
Keyword(s):  
Diabetic Foot ◽  
Bone Biopsy ◽  
Bacterial Load ◽  
False Negative ◽  
Metatarsal Bone ◽  
High Rate ◽  
Microbiological Analysis ◽  
High Tendency ◽  
Metatarsal Bones ◽  
Bone Biopsies

Microbiological cultures of per-wound bone biopsies have shown a lack of correlation and a high rate of false-negative results when compared with bone biopsy cultures in diabetic foot osteomyelitis. The selection of samples from the area of active osteomyelitis, which contains a complete census of the microorganisms responsible for the infection, is essential to properly guide antimicrobial treatment. We aimed to comparatively evaluate the quantitative and qualitative cultures taken from different areas, in metatarsal heads resected for osteomyelitis. For this purpose, we consecutively selected 13 metatarsal heads from 12 outpatients with plantar ulcers admitted to our diabetic foot unit. Metatarsal heads were divided transversally into 3 portions: plantar (A), central (B), and dorsal (C), and the 39 resulting samples were cultured. Qualitative and quantitative microbiological analysis was performed, and the isolated species and bacterial load, total and species specific, were compared between the 3 metatarsal bone segments. The primary outcome of the study was the bacterial diversity detected in the different bone sections. Cultures were positive in 12 of the 13 included metatarsal heads (92%). A total of 34 organisms were isolated from all specimens. Ten of the 12 cultures (83%) were polymicrobial. Ten of the 13 metatarsal heads (77%) had identical microbiological results in each of the 3 bone sections. The largest number of microorganisms was found in the central section. The overall concordance between sections was 91%. The predominant microorganisms were coagulase-negative staphylococci (41%). Statistical differences were not found in the bioburden between sections (range 3.25-3.41 log10 colony-forming unit/g for all sections; P = .511). The results of our study suggest that microorganisms exhibit a high tendency to spread along the metatarsal bone and that the degree of progression along the bone is species dependent. The central portions of metatarsal bones tend to accumulate a higher diversity of species. Thus, we recommend this area of bone for targeted biopsy in patients with suspected osteomyelitis.

scholarly journals miR-15b negatively correlates with lipid metabolism in mammary epithelial cells

2018 ◽  
Vol 314 (1) ◽  
pp. C43-C52 ◽  
Author(s):  
Meiqiang Chu ◽  
Yong Zhao ◽  
Shuai Yu ◽  
Yanan Hao ◽  
Pengfei Zhang ◽  
...  
Keyword(s):  
Lipid Metabolism ◽  
Epithelial Cells ◽  
Steroid Hormones ◽  
Lipid Content ◽  
Mammary Epithelial Cells ◽  
Lipid Production ◽  
Fatty Acid Synthetase ◽  
Lipid Synthesis ◽  
Mammary Epithelial ◽  
Lipid Formation

Mammary epithelial cells are regulated by steroid hormones, growth factors, and even microRNAs. miR-15b has been found to regulate lipid metabolism in adipocytes; however, its effects on lipid metabolism in mammary epithelial cells, the cells of lipid synthesis and secretion, are as yet unknown. The main purpose of this investigation was to explore the effect of miR-15b on lipid metabolism in mammary epithelial cells, along with the underlying mechanisms. miR-15b was overexpressed or inhibited by miRNA mimics or inhibitors; subsequently, lipid formation in mammary epithelial cells, and proteins related to lipid metabolism, were investigated. Through overexpression or inhibition of miR-15b expression, the current investigation found that miR-15b downregulates lipid metabolism in mammary epithelial cells and is expressed differentially at various stages of mouse and goat mammary gland development. Inhibition of miR-15b expression increased lipid content in mammary epithelial cells through elevation of the lipid synthesis enzyme fatty acid synthetase (FASN), and overexpression of miR-15b reduced lipid content in mammary epithelial cells with decreasing levels of FASN. Moreover, the steroid hormones estradiol and progesterone decreased miR-15b expression with a subsequent increase in lipid formation in mammary epithelial cells. The expression of miR-15b was lower during lactation and negatively correlated with lipid synthesis proteins, which suggests that it may be involved in lipid synthesis and milk production. miR-15b might be a useful target for altering lipid production and milk yield.

scholarly journals The Use of Urea and Kelp Waste Extract is A Promising Strategy for Maximizing the Biomass Productivity and Lipid Content in Chlorella sorokiniana

Plants ◽  
2020 ◽  
Vol 9 (4) ◽  
pp. 463 ◽  
Author(s):  
Ali Nawaz Kumbhar ◽  
Meilin He ◽  
Abdul Razzaque Rajper ◽  
Khalil Ahmed Memon ◽  
Muhammad Rizwan ◽  
...  
Keyword(s):  
Lipid Content ◽  
Fossil Fuels ◽  
Fossil Fuel ◽  
Lipid Production ◽  
Total Lipid Content ◽  
Biomass Productivity ◽  
Chlorella Sorokiniana ◽  
Biofuel Production ◽  
Promising Strategy ◽  
Waste Extract

The decline in fossil fuel reserves has forced researchers to seek out alternatives to fossil fuels. Microalgae are considered to be a promising feedstock for sustainable biofuel production. Previous studies have shown that urea is an important nitrogen source for cell growth and the lipid production of microalgae. The present study investigated the effect of different concentrations of urea combined with kelp waste extract on the biomass and lipid content of Chlorella sorokiniana. The results revealed that the highest cell density, 20.36 × 107 cells−1, and maximal dry biomass, 1.70 g/L, were achieved in the presence of 0.5 g/L of urea combined with 8% kelp waste extract. Similarly, the maximum chlorophyll a, b and beta carotenoid were 10.36 mg/L, 7.05, and 3.01 mg/L, respectively. The highest quantity of carbohydrate content, 290.51 µg/mL, was achieved in the presence of 0.2 g/L of urea and 8% kelp waste extract. The highest fluorescence intensity, 40.05 × 107 cells−1, and maximum total lipid content (30%) were achieved in the presence of 0.1 g/L of urea and 8% kelp waste extract. The current study suggests that the combination of urea and kelp waste extract is the best strategy to enhance the biomass and lipid content in Chlorella sorokiniana.

scholarly journals The Antimicrobial Efficacy of four different Intracanal Medication to Microorganisms existing in the Failure of Endodontic Therapy: An in vitro study

2021 ◽  
Vol 8 (3) ◽  
pp. 01-04
Author(s):  
Jorge Paredes Vieyra ◽  
Fabian Ocampo Acosta ◽  
Francisco Javier Jiménez Enriquez ◽  
Alan Hidalgo Vargas ◽  
Ignacio Manriquez Quintana ◽  
...  
Keyword(s):  
Bacterial Load ◽  
In Vitro Study ◽  
Diffusion Test ◽  
Chemical Combination ◽  
Root Canal System ◽  
Inhibition Zones ◽  
Petri Plate ◽  
Micro Organisms ◽  
And Staphylococcus Aureus

Aim.This study aims to identify the efficacy of different intracanal medication formulations existing in end of endodontic therapy’s failure, and related to strains of Enterococcus faecalis, Pseudomonas aeruginosa, and Staphylococcus aureus in Petri plates. Materials and methods. It was used diffusion test in agar where each Petri plate with the inoculated bacteria. Perforations of approximately 4 mm deep by 5 mm in diameter were made to prepare where the intracanal drug (25 µl) to be tested. The diameters of the bacterial inhibition zones were measured and registered to each tested medication at the period of 24 hours, 48 hours, 7 and 14 days respectively. Results. All the medications promoted inhibition halos. The inhibition halos were represented in mm. A higher elimination of micro-organisms can be significantly achieved through the association of different substances in the formulation of an intra canal medication, with emphasis to Ca (OH)2 combined with nitrofurazone and magnesium oxide respectively. Conclusion. Cleaning and shaping of the root canal system associated with the chemical combination of Ca (OH) 2 with antiseptic pastes or solutions considerably reduce the bacterial load.

Optimization of lipid accumulation in Pleurastrum insigne for biodiesel production

2021 ◽  
Vol 16 (10) ◽  
pp. 144-155
Author(s):  
Van Lal Michael Chhandama ◽  
Belur Kumudini Satyan
Keyword(s):  
Lipid Content ◽  
Lipid Production ◽  
Statistical Design ◽  
High Growth ◽  
High Growth Rate ◽  
Biodiesel Production ◽  
Nitrogen And Phosphorus ◽  
Biodiesel Standards ◽  
High Lipid ◽  
Different Sources

Microalgae emerged as a competent feedstock for biodiesel production because of high growth rate and lipid content. This work focuses on isolation of novel microalgal strain from different sources of water for the production of biodiesel. The isolated microalgae, Pleurastrum insigne possessed high lipid content (~28 % dcw), further optimized to 57.06 % dcw using a statistical design (CCD) under Response Surface Methodology. Lipid production was optimized by nutrient (nitrogen and phosphorus) and pH stress. The different type of fatty acids present in the optimized lipid was also profiled using GCMS. Biodiesel yield was found to be 82.14 % of the total lipid and the fuel properties tested have met IS, ASTM and EN biodiesel standards.

scholarly journals Enhanced lipid production by Yarrowia lipolytica cultured with synthetic and waste-derived high-content volatile fatty acids under alkaline conditions

2020 ◽  
Vol 13 (1) ◽  
Author(s):  
Ruiling Gao ◽  
Zifu Li ◽  
Xiaoqin Zhou ◽  
Wenjun Bao ◽  
Shikun Cheng ◽  
...  
Keyword(s):  
Fatty Acids ◽  
Acetic Acid ◽  
Propionic Acid ◽  
Yarrowia Lipolytica ◽  
Butyric Acid ◽  
Lipid Content ◽  
Volatile Fatty Acids ◽  
Lipid Production ◽  
Initial Ph ◽  
Alkaline Conditions

Abstract Background Volatile fatty acids (VFAs) can be effective and promising alternate carbon sources for microbial lipid production by a few oleaginous yeasts. However, the severe inhibitory effect of high-content (> 10 g/L) VFAs on these yeasts has impeded the production of high lipid yields and their large-scale application. Slightly acidic conditions have been commonly adopted because they have been considered favorable to oleaginous yeast cultivation. However, the acidic pH environment further aggravates this inhibition because VFAs appear largely in an undissociated form under this condition. Alkaline conditions likely alleviate the severe inhibition of high-content VFAs by significantly increasing the dissociation degree of VFAs. This hypothesis should be verified through a systematic research. Results The combined effects of high acetic acid concentrations and alkaline conditions on VFA utilization, cell growth, and lipid accumulation of Yarrowia lipolytica were systematically investigated through batch cultures of Y. lipolytica by using high concentrations (30–110 g/L) of acetic acid as a carbon source at an initial pH ranging from 6 to 10. An initial pH of 8 was determined as optimal. The highest biomass and lipid production (37.14 and 10.11 g/L) were obtained with 70 g/L acetic acid, whereas cultures with > 70 g/L acetic acid had decreased biomass and lipid yield due to excessive anion accumulation. Feasibilities on high-content propionic acid, butyric acid, and mixed VFAs were compared and evaluated. Results indicated that YX/S and YL/S of cultures on butyric acid (0.570, 0.144) were comparable with those on acetic acid (0.578, 0.160) under alkaline conditions. The performance on propionic acid was much inferior to that on other acids. Mixed VFAs were more beneficial to fast adaptation and lipid production than single types of VFA. Furthermore, cultures on food waste (FW) and fruit and vegetable waste (FVW) fermentate were carried out and lipid production was effectively improved under this alkaline condition. The highest biomass and lipid production on FW fermentate reached 14.65 g/L (YX/S: 0.414) and 3.20 g/L (YL/S: 0.091) with a lipid content of 21.86%, respectively. By comparison, the highest biomass and lipid production on FVW fermentate were 11.84 g/L (YX/S: 0.534) and 3.08 g/L (YL/S: 0.139), respectively, with a lipid content of 26.02%. Conclusions This study assumed and verified that alkaline conditions (optimal pH 8) could effectively alleviate the lethal effect of high-content VFA on Y. lipolytica and significantly improve biomass and lipid production. These results could provide a new cultivation strategy to achieve simple utilizations of high-content VFAs and increase lipid production. Feasibilities on FW and FVW-derived VFAs were evaluated, and meaningful information was provided for practical applications.

scholarly journals Engineering cytoplasmic acetyl-CoA synthesis decouples lipid production from nitrogen starvation in the oleaginous yeast Rhodosporidium azoricum

2019 ◽  
Vol 18 (1) ◽  
Author(s):  
Silvia Donzella ◽  
Daniela Cucchetti ◽  
Claudia Capusoni ◽  
Aurora Rizzi ◽  
Silvia Galafassi ◽  
...  
Keyword(s):  
Lipid Content ◽  
Nitrogen Starvation ◽  
Neutral Lipids ◽  
Lipid Production ◽  
Industrial Process ◽  
Wild Type ◽  
Lipid Concentration ◽  
Atp Citrate Lyase ◽  
Acetyl Coa ◽  
Engineered Strain

Abstract Background Oleaginous yeasts are able to accumulate very high levels of neutral lipids especially under condition of excess of carbon and nitrogen limitation (medium with high C/N ratio). This makes necessary the use of two-steps processes in order to achieve high level of biomass and lipid. To simplify the process, the decoupling of lipid synthesis from nitrogen starvation, by establishing a cytosolic acetyl-CoA formation pathway alternative to the one catalysed by ATP-citrate lyase, can be useful. Results In this work, we introduced a new cytoplasmic route for acetyl-CoA (AcCoA) formation in Rhodosporidium azoricum by overexpressing genes encoding for homologous phosphoketolase (Xfpk) and heterologous phosphotransacetylase (Pta). The engineered strain PTAPK4 exhibits higher lipid content and produces higher lipid concentration than the wild type strain when it was cultivated in media containing different C/N ratios. In a bioreactor process performed on glucose/xylose mixture, to simulate an industrial process for lipid production from lignocellulosic materials, we obtained an increase of 89% in final lipid concentration by the engineered strain in comparison to the wild type. This indicates that the transformed strain can produce higher cellular biomass with a high lipid content than the wild type. The transformed strain furthermore evidenced the advantage over the wild type in performing this process, being the lipid yields 0.13 and 0.05, respectively. Conclusion Our results show that the overexpression of homologous Xfpk and heterologous Pta activities in R. azoricum creates a new cytosolic AcCoA supply that decouples lipid production from nitrogen starvation. This metabolic modification allows improving lipid production in cultural conditions that can be suitable for the development of industrial bioprocesses using lignocellulosic hydrolysates.

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