Bold Basal Medium Research Articles

Impact of cultivation conditions on biomass yield and lipid content of Scenedesmus obliquus

Microalgae have currently been considered as a promising feedstock for biodiesel production. The accumulation of microalgal lipids is species-specific and largely dependent upon cultivation conditions. The present study aimed to investigate the biomass productivity and lipid content of Scenedesmus obliquus cultivated under nitrogen (N)- and phosphorus (P)-depleted conditions. The highest microalgal density was 38.0 ± 3.5 × 106 cell/mL after 12 days of cultivation in the standard Bold’s Basal Medium (BBM) and significantly decreased with decreasing N conentrations in the media, with the density of 1.4 ± 0.5 × 106, 21.5 ± 1.4 × 106, 25.7 ± 4.9 × 106, and 33.5 ± 1.2 × 106 cell/ mL in the nutrient solutions containing 0, 25, 50, and 75% N, respectively. Conversely, the P concentrations showed negligible effects on the growth of S. obliquus across all treatments. Overall, the lipid accumulation of S. obliquus increased with decreasing N and P concentrations. The results revealed that N-starvation yielded the highest microalgal lipid content of 184.1 ± 17.4 mg/g d.w., whereas that under N-sufficient condition was only 80.0 ± 9.8 mg/g d.w. Likewise, the lipid content was almost double when S. obliquus was grown in the modified BBM containing half of P concentration of the standard medium. Taken together, this study demonstrates that alteration of the nutrients is an effective approach for enhancing lipid accumulation in S. obliquus.

Optimisation of Bioflocculation Using Anabaena sp. and Navicula sp. for Harvesting of Glagah Microalgae Consortium

One of the problems in microalgae is harvesting. Currently, many chemical methods are used that impact the environment. Not all of them can be used as a filter, so bioflocculation is used because there is no need to change the medium. This method is an environmentally friendly and efficient alternative to chemical flocculants that usually cause contamination of biomass and health. Previous studies have shown that different ratios of auto-flocculated microalgae in cocultures affect the flocculation rate. This research was carried out by the Glagah Consortium bioflocculation using Anabaena sp. and Navicula sp., which had never been done before. The study aims to study the effect of the mixing ratio on the flocculation rate, carbohydrates, and lipid content of the Glagah Consortium. The consortium uses Anabaena sp. and Navicula sp. as bioflocculants. Glagah and Anabaena sp. consortium was cultured in Bold Basal Medium, while Navicula sp. was cultured in F/2 medium. Cell density was measured every 24 hr for 8 days with a hemocytometer. The cultures were harvested in the stationary phase, then mixed between non-flocculated microalgae (Glagah Consortium) and flocculated microalgae (Anabaena sp., Navicula sp.) in a ratio of 1:1, 1:0.5, and 1:0.25 for 24 hr. Bioflocculation was measured by spectrophotometer at 750 nm 0 and 24 hr after mixing. Carbohydrate levels were measured using the phenol sulfuric acid method, while lipid measurements were performed using the Bligh and Dyer method. The addition of Anabaena sp. and Navicula sp. as bioflocculant in Glagah Consortium culture results in an increase in flocculation rate with an effective ratio of 1:0.25 for Anabaena sp. (81%) and 1:1 for Navicula sp. (95%). Mixing of Anabaena sp. and Glagah Consortium results in carbon source competition, reducing carbohydrate content at higher mixing ratios (0.172, 0.364, and 0.500 mg/ml on 1, 1:0.5, and 1:0.25) while increasing lipid content as a result of lipid production in stationary phase (highest on ratio 1:1 = 0.011 mg/ml). Navicula sp. and Glagah Consortium mixture caused no significant changes to carbohydrate content but showed an increased amount of lipid at all ratios as a result of osmotic stress on Glagah Consortium from saline F/2 medium (highest on ratio 1:1 = 0.162 mg/ml).

Influence of Nutrients in Microalgae Cultivation by SEM and EDX Evaluation

Microalgae have recently attracted a lot of attention on a global level because of their numerous application possibilities in the renewable energy, biopharmaceutical, and nutraceutical industries. Microalgae can be exploited to make biofuels, bioactive medicines and food additives at a low cost and with no environmental harmful impact. The media’s nutritional content affects the development of microalgae. The role that macro- and micro-nutrients play in the cultivation of microalgae is also significant. For microalgae cultivation, a sample of river water was collected, BG11 and Bold Basal Media (BBM) synthetic media were prepared. Observations of microalgae growth were made after 15 days. On samples of raw water and microalgae grown in a lab, Scanning Electron Microscopy (SEM) and Energy-Dispersive X-ray spectroscopy (EDX) were conducted. Raw water and microalgae sample structures were detailed by SEM results, and both samples’ chemical compositions were shown by EDX results. The cultivation of microalgae depends heavily on macro and micro nutrients. The growth of microalgae was accelerated in the presence of nutrients.

Phycoremediation of crude oil polluted water from selected water sources in Ogoniland, Rivers State, Nigeria.

Crude oil exploitation in the Niger Delta, particularly in Ogoniland, brought environmental devastation occasioned by petroleum pollution, as farmlands and water sources were destroyed. This study was designed to remediate crude oil contaminated water obtained from water sources in Ogoniland using two green algal species. Thirty water samples were collected from eight different water sources. The samples were analysed for total petroleum hydrocarbon (TPH) using gas chromatography/flame ionization detector (GC/FID). Algal samples were collected from Ogba River and at wetland in Military Hospital Benin, Edo State, Nigeria. The algal samples were identified, screened, optimized and grown in Bold basal medium. Results obtained from the determination of TPH showed that the infiltrated pond (Exc) sample site had the highest concentration among all the sites sampled with 198.8329 μg/L, R2 with 134.1296 μg/L, R1 with 108.9394 μg/L, R3 with 105.8011 μg/L, R4 with 98.442 8 μg/L, the hand-dug wells (Wll) had 9.6586 μg/L while the borehole (Bhl) had the lowest with 1.8310 μg/L. It was deduced that pollution of water sources was principally because of pollutants washed from the soil environment into the open surface water sources via run-off rather than through the seepage from the underground aquifers, incriminating illegal oil mining and artisanal refining. Results obtained from the analysis of algal growth medium indicated that the two algal species were able to absorb the hydrocarbon contaminants, albeit at different rates, corresponding with the algal growth rate. Analysis of algal biomass after 4 weeks of remediation showed that from the initial 10.27 μg/20 mL added to the growth medium, the highest TPH mean value of 0.490 μg/20 mL was extracted from Ulothrix zonata (F.Weber & Mohr) Kützing biomass grown in Exc compared to 0.344 μg/20 mL of TPH extracted from Chlorella sorokiniana Shihira & R.W.Krauss grown in the same sample site. Also, Ulothrix zonata had higher TPH yield 0.023 μg/20 mL in Bhl compared to Chlorella sorokiniana 0.021 μg/20 mL of TPH from the same water source. This result indicated Ulothrix zonata had superior TPH phycoremediation ability to Chlorella sorokiniana. While the present study calls for deployment of the algal species for field trial, it is strongly recommended that crude oil pollution should be discouraged.

Screening of wastewater Oedogonium oblangum algae for hyper-oil transformation into biodiesel by response surface methodology

The algae have gained more significance as a renewable third-generation feedstock for being easily available and a hyper-production source for lipids and biodiesel. Sustainable and cost-effective production of algal biodiesel requires screening and optimization of various culture conditions. Screening of algae on the basis of its lipid content is crucial for exploring its potential for production of biodiesel. In the current study, the screening of six indigenous algal strains was performed based on lipid contents, out of which Oedogonium oblangum (O. oblangum) exhibited hyper-lipid content (15.76%). Bold basal media and wastewater media were compared as culture media to evaluate the growth of O. oblangum; the respective strain showed better growth on wastewater media, therefore, this media was used for further experimentation. A laboratory-based integrated approach was used to enhance production of algal lipids by applying the effects of temperature, pH, and wastewater dilutions. The oil contents were interestingly improved under the optimal culture conditions of temperature (25°C), pH (6.5), wastewater dilution (45%) with oil contents of 18.35%, 17.15%, and 17.95%, respectively. The extracted oil was transformed into biodiesel by alkali-mediated transesterification reactions using four factors (Oil/methanol ratio, temperature, time, and catalyst) by response surface methodology (RSM). The RSM successfully optimized the transesterification reactions with 86.73% of biodiesel under optimal conditions of oil/alcohol ratio (1:7.6 v/v), temperature (60.5°C), time (59 ​min), and catalyst (0.53 ​wt. %). Physical properties of biodiesel (kinematic viscosity; 5.17; acid value; 0.63; flash point; 152; specific gravity; 0.74; calorific value; 42.11; and water contents; 0.03) comply with the ASTM standards and lead to enhance the quality of produced biodiesel. The optimized culture conditions, transesterification reactions, and wastewater medium can be employed for the economically production of biodiesel at commercial scale. Overall, the results showed that biodiesel derived from an indigenous novel algal strain, O. oblangum, has the potential to compete and replace commercially available petro-diesel using wastewater media. It might contribute to resolve the energy challenges being faced by Pakistan and the entire world.

Effects of Rotten Vegetable-Based Low-Cost Media on the Growth and Morphology of an Astaxanthin-Producing Green Alga, Monoraphidium Littorale

Growing microalgae on vegetable waste (rotten potatoes) media is not only a plausible technique to replace expensive commercial media but also a way of reducing feed costs for rearing zooplankton and fish larvae in aquaculture. As a way of starting an inevitable step up, Monoraphidium littorale was grown in 25% (T1), 50% (T2), and 75% (T3) of digested rotten potato supernatant (DRPS) and at the same time in Bold Basal Medium (BBM) as a control (T4) for 16 days. The highest cell density of M. littorale was recorded in T1, followed by T4, T2, and T3. A similar increasing trend of chlorophyll-a and optical density was also observed during the experimental period. The study also ascertained T1 as a potential growth medium where M. littorale showed superior biomass production which was significantly higher ( P < 0.05 ) than other treatments. It was also worth mentioning that the highest ( P < 0.05 ) protein content was determined in T1 at the end of the cultivation time. Similarly, a highly significant difference ( P < 0.05 ) was also found in the lipid content of the microalgae grown in T1 and T4. Furthermore, the morphology of the cells of M. littorale was found to be strongly affected by the DRPS concentrations and BBM. Thus, the lower concentration of the DRPS served as the best medium for enhancing the growth and biomass of M. littorale. Consequently, to expedite the sustainable progression of microalgal production, cost-effective culture techniques by using different wastes may be adopted.

Isolation of phosphorus-hyperaccumulating microalgae from revolving algal biofilm (RAB) wastewater treatment systems.

Excess phosphorus (P) in wastewater effluent poses a serious threat to aquatic ecosystems and can spur harmful algal blooms. Revolving algal biofilm (RAB) systems are an emerging technology to recover P from wastewater before discharge into aquatic ecosystems. In RAB systems, a community of microalgae take up and store wastewater P as polyphosphate as they grow in a partially submerged revolving biofilm, which may then be harvested and dried for use as fertilizer in lieu of mined phosphate rock. In this work, we isolated and characterized a total of 101 microalgae strains from active RAB systems across the US Midwest, including 82 green algae, 9 diatoms, and 10 cyanobacteria. Strains were identified by microscopy and 16S/18S ribosomal DNA sequencing, cryopreserved, and screened for elevated P content (as polyphosphate). Seven isolated strains possessed at least 50% more polyphosphate by cell dry weight than a microalgae consortium from a RAB system, with the top strain accumulating nearly threefold more polyphosphate. These top P-hyperaccumulating strains include the green alga Chlamydomonas pulvinata TCF-48 g and the diatoms Eolimna minima TCF-3d and Craticula molestiformis TCF-8d, possessing 11.4, 12.7, and 14.0% polyphosphate by cell dry weight, respectively. As a preliminary test of strain application for recovering P, Chlamydomonas pulvinata TCF-48 g was reinoculated into a bench-scale RAB system containing Bold basal medium. The strain successfully recolonized the system and recovered twofold more P from the medium than a microalgae consortium from a RAB system treating municipal wastewater. These isolated P-hyperaccumulating microalgae may have broad applications in resource recovery from various waste streams, including improving P removal from wastewater.

Bioelectricity generation by using cellulosic waste and spent engine oil in a concentric photobioreactor-microbial fuel cell

Microbial fuel cells (MFC) can be a potential technique to harvest energy from waste organic biomass. Organic waste is a good source of carbon in the form of simple and complex polysaccharides. In this study, newspaper powder, dried dead microalgae biomass and mixed fruit peel powder were separately targeted as substrate for the growth of an isolated cellulolytic bacteria inside the anode chamber of three different MFCs. At cathode, bold basal medium with spent engine oil was used as catholyte. An isolated and acclimatized microalgae was used as cathode biocatalyst in order to perform bioremediation of spent engine oil wastewater at cathode chamber. The MFC with newspaper powder showed highest maximum power density of 34.88 ± 1.00 mW/m2. Both fruit peel powder and dried microalgae powder-based MFCs achieved almost parallel maximum power densities of 15.57 ± 0.49 mW/m2 (at 161.1 ± 2.54 mA/m2) and 16.00 ± 0.32 (at 163.3 ± 1.66 mA/m2), respectively. The anode chambers of all MFCs reflected chemical oxygen demand (COD) removal efficiencies in range of 65–86 %. At anode chamber, maximum COD removal of 86.25 % was achieved by microalgae powder based MFC. The removal percentage of oil and grease at cathode chamber were 37.7 %, 42.3 % and 29.1 % for fruit peel, newspaper powder and microalgae powder based MFCs respectively. Up to 76–80 % nitrate-nitrogen, 96–97 % ammonium-nitrogen, 90–94 % phosphate-phosphorous removal were observed at cathode chamber in all the MFCs. Microbial community analysis revealed that Proteobacteria, Firmicutes and Bacteroidetes were the dominant phyla present in all the three anodic biofilms.

Screening of best growth media for Chlorella vulgaris cultivation and biodiesel production

The goal of the present research was to screen the best growth media for Chlorella vulgaris and investigate their effects on growth parameters like biomass yield, lipid, carbohydrate, protein, chlorophyll, and carotenoids production. Four different growth media were selected: bold basal medium (BBM), BG-11, M-8, and Modified BG-11 for the present study. In BBM, the maximum protein and lipid concentrations were 0.0352 mg ml−1 and 14.646% dcw, respectively, were obtained. In comparison to other selected growth media, BG-11 had the highest biomass productivity (1.148 g L−1), carbohydrate (0.059 mg ml−1), chlorophyll (13.233 µg ml−1) and carotenoid (1.228 mg L−1) content. Due to its biochemical properties, Chlorella vulgaris is used in various applications and has several practical uses like biofuel production, pharmaceutical etc. When microalgae are grown in different growth media, its metabolism changes as per the components of growth media. This study shows the effect of growth media on C. vulgaris growth in terms of biomass production and lipid production.

Energy from Waste: Poterioochromonas malhamensis Used for Managing Dairy Effluent and Producing Valuable Microalgal Lipid

Currently, microalgae have become a marvelous and resource-friendly alternative source of advantageous bioproducts, such as lipids, carbohydrates, proteins, or other bioactive compounds. Because of the richness of microalgae in these high-value-added metabolites, still, it is an underdeveloped source of sustainable energy and food. There are some hurdles to profitable production, such as culture contamination and costly harvesting techniques. In the current work, a chrysophyte was isolated from dairy wastewater, identified as Poterioochromonas malhamensis based on its morphology and partial 18S rRNA gene sequences. This isolate was used to remediate dairy waste water (DWW) and to obtain neutral lipids (fatty acids) from microalgae. Microalgal growth was optimized by using different concentrations of DWW, supplemented with all the nutritive requirements for better progression and flourishment. Maximum biomass yield 1.478 g L−1 was achieved by optimized cultural conditions (different concentrations of DWW with BBM media). This strain showed high nitrate and phosphate removal efficiency (87.45% and 88.96%), respectively in 15 days. The experimental results highlighted that the lipid content and the chemical oxygen demand (COD) removal were 31.60% and 88.84%, respectively, and the lipid profile of isolated microalga was C16:0, C16:1, C18:0, C18:1, and C18:2 fatty acids. For growth and treatment purposes, 75% DWW with Bold’s Basal Medium (BBM) media showed better results. This is the first report of DWW treatment using the microalga Poterioochromonas malhamensis, as far as we are aware. Its cultivation prevented the spread of pollution of freshwater sources, remedied the DWW, and generated important lipids for industry.

Replacing expensive synthetic media with banana stem compost extract medium for production of Chlorella vulgaris

ABSTRACT Microalgal cultivation by small scale aquaculture farmers is limited by the high cost of synthetic culture media. The current study was conducted to investigate use of banana stem compost extract (BSCE) as an alternative medium for cultivation of the microalga Chlorella vulgaris. C. vulgaris was batch cultured for 24 days in the laboratory using synthetic Bold Basal Medium (BBM) as a control and BSCE at concentrations of 2%, 5% and 10% (by volume) as the treatments. Algal growth was evaluated by measuring dry cell weight and specific growth rate (SGR) during the experimental period. Chemical composition was analysed following standard analytical methods. Variations in growth trends among culture media were attributed to variations in nutrient concentration and lack of acclimatization period. Some macro- and micronutrients in BSCE-cultivated C. vulgaris were higher than or similar to those observed in BBM-cultivated algae. The macronutrients differed among BSCE treatments. It was concluded that BSCE can be used as the culture medium, providing similar nutritional value and supporting similar growth performance to synthetic media. However, selection of BSCE concentration should be based on macronutrients and take into account the intended use of cultivated microalgae.

Application of Chlorella vulgaris for nutrient removal from synthetic wastewater and MBR-treated bio-park secondary effluent: growth kinetics, effects of carbon and phosphate concentrations

Application of Chlorella vulgaris for polishing secondary effluent of a wastewater treatment (containing C, N and P) was investigated. As a first step, batch experiments were conducted in Bold's Basal Media (BBM) to quantify the effects of orthophosphates (0.1-107mg/L), organic carbon (0-500mg/L as acetate) and N/P ratio on the growth of Chlorella vulgaris. The results revealed that the orthophosphate concentration was found to control the removal rates of nitrates and phosphates; however, both were effectively removed (> 90%) when the initial orthophosphate concentration was 4-12mg/L. The maximum nitrate and orthophosphate removals were observed at an N:P ratio of ~ 11. However, the specific growth rate (µ) was significantly increased (from 0.226 to 0.336g/g/day) when the initial orthophosphate concentration was 0.1-4.3mg/L. On the other hand, the presence of acetate had significantly improved the specific growth and specific nitrate removal rates of Chlorella vulgaris. The specific growth rate increased from 0.34g/g/day in a purely autotrophic culture to 0.70g/g/day in the presence of acetate. Subsequently, the Chlorella vulgaris (grown in BBM) was acclimated and grown in the membrane bioreactor (MBR)-treated real-time secondary effluent. Under the optimised conditions, 92% nitrate and 98% phosphate removals (with a growth rate of 0.192g/g/day) were observed in the bio-park MBR effluent. Overall, the results indicate that coupling Chlorella vulgaris as a polishing treatment in existing wastewater treatment units could be beneficial for highest level of water reuse and energy recovery goals.

Vitality and growth rate of agar plate-cultivated Antarctic microautotrophs: Analysis of PSII functioning by chlorophyll fluorescence parameters

In our study, we focused on the growth of three different microautotrophs isolated from Antarctic lichens (Placopsis contortuplicata, Solorina spongiosa) and cryptoendolithic algal vegetation. The isolates were purified and inoculated on agar plates, Bold´s Basal Medium (BBM). The growth of the cultures and the markers of physiological (photosynthetic) activity were monitored by chlorophyll fluorescence in 1 week intervals for 3 months after inoculation. For the assessment of photosynthetic activity, the method of slow Kautsky kinetics supplemented with saturation pulses was applied. Four chlorophyll fluorescence parameters calculated: (1) maximum quantum yield of PSII (FV/FM), (2) effective quantum yield of photosynthetic processes in PSII (ΦPSII), (3) non-photochemical quenching of chlorophyll fluorescence, and (4) background chlorophyll fluorescence ratio (F0/F0´). Troughout the cultivation period, the maximum quantum yield of PSII (FV/FM) showed high values in all three autotrophs with only slight increase in the first part of the cultivation period, followed by slight decrease in the second part. The ΦPSII values showed a rapid decline within the first 4 weeks of cultivation followed by more or less constant values in the isolates from P. contortuplicata and cryptoendolithic alga. Contrastingly, time course of ΦPSII rather showed an increase followed by a decrease in S. spongiosa isolate. NPQ (related to the activation of protective mechanisms) increased in the second part of cultivation period, the rate of increase and maximum values were species-specific. The species-specific differences in chlorophyll fluorescence parameters are discussed as well as their potential for evaluation of photosynthetic performance of in vitro cultivated algal/cyanobacterial cultures on agar plates.

Integrated approach for enhanced crude bio-oil yield from microalgae cultivated on the aqueous phase of hydrothermal co-liquefaction with agar-free seaweed residues

The present study evaluated the efficiency of microalgae cultivation on the aqueous phase (Aq-LP) produced from (Co-)hydrothermal liquefaction (HTL) of agar-free seaweed waste. Optimization of bio-oil production from Co-HTL of seaweed residue with the studied microalgal biomass grown in Bold's Basal Medium (BBM) was initially carried out using Box-Behnken model. The highest bio-oil yield of 42.21% was recorded by HTL of microalgal biomass at 250 °C for 60 min, which showed insignificant difference with that from Co-HTL. Comparatively, Aq-LP from microalgal biomass showed the highest organic load with total organic carbon of 11.69 g L−1, while that from seaweed residue showed the lowest value of 7.47 g L−1. However, mineral ions in the Aq-LP from seaweed residue showed higher values compared to microalgal biomass. Therefore, Co-HTL enriched the Aq-LP with nutrients from both feedstocks which resulted in 10.3% higher biomass yield than the control. The experimental bio-oil yield was 15.3% higher than the calculated value, which confirms a synergistic action during Co-HTL. In addition, the quality of the bio-oil obtained via HTL was improved after Co-HTL of both feedstocks. Results estimated that the higher biomass yield of microalgae due to cultivation in Co-HTL Aq-LP could promote the final bio-oil volumetric yield to 891 kg m−3, comparing to 819 kg m−3 using the synthetic medium.

Valorization of environmental-burden waste towards microalgal metabolites production

The present study develops a novel concept of using waste media as an algal nutrient resource compared to the usual growth media with the aid of growth kinetics study and metabolite production abilities. Food- and agri-compost wastes are compact structures with elemental compounds for microbial media. As a part of the study, environ-burden wastes (3:1) as a food source for photosynthetic algae as a substitute for the costly nutrient media were proposed. The environment-burden waste was also envisaged for macromolecule production, i.e., 99200 μg/ml lipid, 112.5 μg/ml protein, and 8.75 μg/ml carbohydrate with different dilutions of agri-waste, bold basal media (BBM), and Food waste, respectively. The fabricated growth kinetics and dynamics showcased the unstructured models of different photosynthetic algal growth phases and the depiction of productivity and kinetic parameters. The theoretical maximum biomass concentration (Xp) was found to be more (0.871) with diluted agricompost media than the usual BBM (0.697). The XLim values were found to be 0.362, 0.323 and 0.209 for BBM, diluted agri-compost media and diluted food waste media, respectively. Overall, the study proposes a cleaner approach of utilizing the wastes as growth media through a circular economy approach which eventually reduces the growth media cost with integrated macromolecule production capabilities.

Utilisation of Fermented Wheat Bran Extract Medium as A Potential Low-cost Culture Medium for Chlorella ellipsoidea

Microalgae, Chlorella ellipsoidea is an excellent energy source for food and biofuel production. Nevertheless, the production cost of C. ellipsoidea using Bold's Basal Medium (BBM) is expensive, which led to the exploration of alternative low-cost medium for large-scale production. Low-cost fermented wheat bran extract medium (FWBEM), which has good nutritional properties, might be an alternative feedstock for mass production of C. ellipsoidea. The present study was conducted to evaluate the growth and production of C. ellipsoidea using different concentrations of FWBEM. Wheat bran was fermented at the concentration of 8.33, 6.66, and 5.00 g/L water labelled as T2, T3, and T4, respectively. The BBM was used as the control medium (T1). The growth and production of C. ellipsoidea were monitored for three days in terms of cell dry weight, specific growth rate, optical cell density, chlorophyll a content, and cell numbers. Those growth data revealed that C. ellipsoidea cultured at 6.66 g/L (T3) did not vary significantly with the standard inorganic BBM. However, T2 and T4 showed substantially lower cell growth and chlorophyll a content than control and T3. Compared to the BBM, a significant reduction in production cost was obtained in the FWBEM. Based on the cell biomass growth, pigmentation, and production cost, FWBEM at a 6.66 g/L could be used as an alternative medium. Therefore, FWBEM has excellent potential to be used for the low-cost production of C. ellipsoidea.

Scenedesmus obliquus and Chlorella vulgaris – A Prospective Algal Fuel Source

In recent years, the prospective use of algae as an alternate fuel source for petroleum-based fuels has increased drastically. It has been researched extensively and proven that it can be used as a sustainable feedstock for producing green energy considering environmental safety. This article focused on the economically viable algal feedstock for the production of lipid content for its use as a feedstock for biodiesel production. For this purpose, the algal species Scenedesmus obliquus and Chlorella vulgaris were selected, and it was grown under lab and open ambient conditions with two Blue green Medium (BG-11) and Bold Basal medium (BBM). Upon the yield, it was noticed that the BG-11 medium gave optimum lipid yield for both species. Hence, it was determined that through this medium higher lipid yield can be expected, and based on the GC-MS result it was notified that it can be a viable source of alternate fuel.

Phycoremediation of cashew nut processing wastewater and production of biodiesel using Planktochlorella nurekis and Chlamydomonas reinhardtii

The present study examined the biomass enrichment of two microalgal strains, Planktochlorella nurekis and Chlamydomonas reinhardtii in cashew nut processing wastewater (CNPW) along with the simultaneous production of biofuel as well as wastewater treatment. The strains were initially grown in Bold's Basal Medium (BBM) before being introduced into CNPW under experimental conditions. The physico-chemical parameters, heavy metal concentration and biomass content were analyzed periodically. The produced biomass was used for the production of biodiesel and the Fatty acid methyl esters (FAME) of the biodiesel were estimated along with its quality. The results of the study revealed a significant improvement in the quality of CNPW within 13 days. P. nurekis (1.914 ± 0.02 g/L) showed higher biomass production than C. reinhardtii (1.503 ± 0.069 g/L). The physico-chemical analysis showed that P. nurekis and C. reinhardtii could significantly reduce nitrate, phosphate and COD from CNPW. The percentage reduction of heavy metals such as Cd, Cr, Ni, Cu and As were 93.2 %, 99.7 %, 98.7 %, 99 % and 90.6 %, respectively when treated with P. nurekis. Similarly, the percentage reduction of the aforesaid heavy metals by C. reinhardtii were 75.7 %, 65.9 %, 72.5 %, 78.5 % and 87.4 % respectively. The FTIR analysis revealed the presence of the functional groups such as amines, alkenes, carboxylic acid, phenol, nitro compound, amide and alcohols in both strains. The FAME profile of both strains showed a moderate concentration of C16–C18 fatty acids content. The quality analysis of biodiesel produced by both species revealed that all the physical properties were within the permissible limits as per ASTM D6751–02 and EN 14214. Comparatively, P.nurekis exhibited notable phycoremediation capacity as well as lipid production potential than C. reinhardtii. The present study has shown that both species are the promising candidates for wastewater treatment.

Effect of Growth Media and pH on Microalgal Biomass of Chlorella vulgaris for Biodiesel Production

The increased industrialization and overuse of natural resources for energy, such as fossil fuels, have led to the energy crises and environmental issues that plague the world in the twenty-first century. The production of biodiesel from algae has recently gained attention as a potentially useful alternative fuel that is both environmentally friendly and easy to obtain. In this work, the effects of various pH levels on algae biomass and oil production from Chlorella Vulgaris were studied. The growth of the biomass concentration was monitored using a spectrophotometer. The biomass of C. vulgaris obtained from the test was subjected to oil extraction using the chemical solvent method. Out of the five media compositions tested (MBG-11, BG-11, BBM, M8 and N8), MBG-11 recorded the highest biomass concentration at pH 8 (0.6 mg/L/D) and N8 recorded the least biomass concentration at pH 6 (0.49 mg/L/D). The highest percentage of oil was extracted from the C. vulgaris in BBM at pH 6 (31.22%) while the lowest oil was recorded in M8 at pH 8 (14.75%). In conclusion, the best medium for C. vulgaris biomass production was MBG-11 medium while the best medium for oil Production from this microalga was Bold Basal Medium (BBM).

Evaluation of the properties on carrageenan bio-films with Chlorella vulgaris blending

Microalgae are multicellular species that exist individually or in groups which typically found in freshwater and marine systems and a good and highly potential source to produce bio-films. Bio-films with carrageenan possessed several drawbacks that needed to be encountered. The purpose of this study is to observe the number of microalgae cell influenced the performance of the bio-film obtained. Cultivation of free cell C. vulgaris microalgae was conducted in Bold’s Basal Medium (BBM) for 16 days. Growth curve of the C. vulgaris, lipid extraction and FAMES determination was conducted on the alternate days of cultivation. 3 mL of C. vulgaris microalgae was added into the formulation of carrageenan at the alternate days of cultivation (D-0, 4, 8, 12, and 16). Results shows, the number of cell, percentage oil yield and FAMEs amount of C. vulgaris at D-16 is the highest which 1.19 × 1010 cell/mL, 27.74% and 17.76 mg/g, respectively. Hence affect the tensile strength of the bio-film and the solution viscosity with 36.26 Mpa and 245.29 mpa/s, respectively. It also shows the lowest value of moisture content which increases the EAB of the biofilm with 10.99% moisture and 50.24% elasticity. With the high number of cell shows the film has the highest value of water contact angle with 107.11°. It also requires the highest activation energy (42.16 kJ/mol) to decompose (80.63%). This can be concluded that the higher the number of cell and percentage oil yield with high amount of FAMEs, the better surface hydrophobicity of the bio-films obtained.