Bold Basal Medium Research Articles

Cultivation of Microalgae Mixed Culture from Mahoni Small Lake UI Campus Depok using Zeolite Substrate with Varying Pb Concentration

Research on the cultivation of mixed cultures of Situ (small lake) Mahoni UI Campus Depok has been done. This research was a preliminary study to measure and compare the growth of Situ Mahoni mixed cultures microalgae grown in Bold's Basal Medium (BBM) with addition of zeolite and without addition of zeolite, and varying concentrations of heavy metal Pb. The concentrations of heavy metal Pb used were 0 ppm, 20 ppm, 40 ppm, 60 ppm, 80 ppm, and 100 ppm for two treatments. The results of this research were that the growth of mixed cultures with the addition of zeolite had the highest abundance of 8.800 cells/mL on day 5 (T5) at a Pb concentration of 40 ppm. Meanwhile, the growth of mixed culture without the addition of zeolite had the highest abundance of 21.700 cells/mL on day 10 (T10) at a Pb concentration of 60 ppm. The growth of microalgae mixed cultures in the medium without addition of zeolite was higher than using zeolite. The activation of zeolite pores causes the microalgae growth is relatively lower. This work aimed to study the growth of a mixed cultures microalgae in varying concentrations of Pb with and without the addition of zeolite

Isolation, Extraction of Oil and Production of Biodiesel from Microalgae

This work is aimed at producing biodiesel from microalgae using Bold Basal Medium. After a month of cultivation, isolation, and harvesting, the microalgae were processed (oil was extracted using a chemical extraction procedure including alcohol with a 96% alcohol content and n-hexane). Transesterification was employed to produce the biodiesel from the extracted algal oil, and the resulting fuel was characterized. The results show that Chlorella sp, Desmid sp and Ankistrodesmus sp were isolated, density, viscosity, acid value, saponification, free fatty acid, peroxide value, iodine value, impurity level, and moisture content of Chlorella sp, Desmid sp and Ankistrodesmus sp oil were (0.805, 0.702, 0.716), (4.92, 4.45, 4.22), (1.51, 1.61, 1.62), (179.8, 178.61, 186.60), (0.86, 0.87, 0.88), (28.6, 28.9, 28.8), (0.31, 0.35, 0.33), (0.90, 0.80, 0.88) and (0.30, 0.36, 0.24) respectively, biodiesel had cetane number (126,125,127), density (0.79, 0.88, 0.87), flash point (126, 127, 125), calorific value (38.39, 38.68, 38.72), and viscosity (2.43, 2.66, 2.33) respectively, the quantity of biodiesel produced varied across all the replicates as the mean difference were less than the standard mean of 2.074. The production of biodiesel is practically possible in Nigeria, and the government should set up companies so as to diversify the oil sector and reduce pollution. The major limitation in this research work was using the traditional method for the isolation and identification of dominant microalgae instead of the molecular method.

Maximizing resource efficiency with dairy and municipal wastewater as nutrient media for Chlorella vulgaris with simultaneous CO2 sequestration

Addressing critical environmental challenges such as greenhouse gas emissions, global warming, and eutrophication demands urgent and innovative solutions. In recent years, microalgae have emerged as a promising avenue for addressing these pressing issues. In this study, the combination of dairy and municipal wastewater is proposed as a culture medium for cultivating microalgae strains capable of sequestering atmospheric CO2. Specifically, the growth of Chlorella vulgaris was investigated using Bold's basal medium, along with varying concentrations of municipal and dairy wastewater, both with and without CO2 supplementation, to assess their CO2 capture potential. Concurrently, the efficiency of chemical oxygen demand (COD), total nitrogen, potassium, and phosphate removal from the wastewater was evaluated. Additionally, the combination of wastewater media with CO2 supplementation yielded the highest CO2 uptake rates, indicating the feasibility of simultaneous CO2 capture during microalgae cultivation. Media composition with 25% municipal wastewater: 75% dairy wastewater supplemented with CO2 demonstrated superior COD elimination with a higher percentage of nutrient removal from wastewater compared to other wastewater proportions. The nutrient removal capacity of aforementioned media also comes in line with high CO2 sequestration rate (13.57 mg L−1 h−1). These findings underscore the potential of utilizing wastewater from diverse sources as a viable culture medium for microalgae cultivation, facilitating concurrent CO2 capture and wastewater treatment.

Soy whey and brewer’s spent grain hydrolysates wholly replace conventional medium for microalgae growth: Process performance and economic considerations

To enhance circularity in heterotrophic microalgal bioprocesses, this study completely substituted glucose and Bold’s basal medium (BBM) with brewer’s spent grain (BSG) and soy whey (SW) hydrolysates. Mild acid hydrolysis conditions of BSG (0.2 M H2SO4, 130 °C, 36 min) and SW (0.1 M HCl, 95 °C, 30 min) were optimised for glucose release, and their hydrolysates were optimally mixed (15 % SW-85 % BSG) to obtain a medium that best supported Auxenochlorella protothecoides growth. Maximum biomass production (Xmax) and productivity (PXmax) obtained in the hydrolysate medium containing 50.75 g/L endogenous glucose (Xmax: 22.17 g/L; PXmax: 7.06 g/L/day) were comparable to that in BBM containing 50.44 g/L exogenous glucose (Xmax: 20.02 g/L; PXmax: 6.34 g/L/day). Moreover, estimated hydrolysate medium production costs were within an order of magnitude to BBM. Overall, the integrated approach of tailored hydrolytic treatments and complementary side-streams presents a promising technical and economic feasibility, with applications extending beyond A. protothecoides.

Two-step polyhydroxybutyrate production from hydrogenic effluent by freshwater microalgae Coelastrella sp. KKU-P1 and Acutodesmus sp. KKU-P2 under mixotrophic cultivation

This study aimed to produce PHB using hydrogenic effluent discharged from the biohydrogen production process with freshwater microalgae including Coelastrella sp. KKU-P1, and Acutodesmus sp. KKU-P2. Batch experiments explored the influence of initial pH and hydrogenic effluent concentration, revealing optimal conditions at 10 % (v/v) effluent concentration and a pH of 6.5 for both KKU-P1 and KKU-P2. Subsequently, medium formulation and photoperiods were optimized to maximize biomass and PHB accumulation. The results showed that the optimal condition for PHB accumulation with KKU-P1 and KKU-P2 was nitrogen phosphorus (NP)-limited Bold's Basal Medium (BBM) under dark conditions. A two-step PHB accumulation in the upscale bioreactor was investigated under optimal conditions. The results showed that KKU-P1 achieved maximum PHB, protein, carbohydrate, and lipid contents of 4.57 %, 29.37 %, 24.76 %, and 13.21 %, respectively, whereas KKU-P2 achieved 6.35 %, 31.53 %, 16.16 %, and 4.77 %, respectively. Based on these findings, it appears that a mixotrophic approach under nutrient-limiting conditions is effective for PHB production in both KKU-P1 and KKU-P2 strains.

Biochemical and Antioxidant Characteristics of Chlorococcum oleofaciens (Chlorophyceae, Chlorophyta) under Various Cultivation Conditions.

The functional state of enrichment cultures of the Chlorophycean strain Chlorococcum oleofaciens CAMU MZ-Ch4 under various cultivation conditions was studied. Experiments with different aeration conditions, cultivation durations, and nitrogen and phosphorus concentrations in the medium were carried out to evaluate the growth dynamics of the strain and its biochemical characteristics. The contents of chlorophylls, carotenoids, proteins, lipids, retinol, α-tocopherol, ascorbic acid, phenolic compounds, lipid peroxidation products, antioxidant enzymes (glutathione peroxidase, catalase, superoxide dismutase), and succinate dehydrogenase activity were measured. The lipid content on the fully supplemented Bold's basal medium increased to 381.03 mg g-1 dry weight at the late stationary growth phase. This value is 1.3-2.8 times higher than in other experiments. The use of aeration was associated with an increased content of proteins at 283.56 mg g-1 and of carotenoids at 2.12 mg g-1. Also, cultures at the early stationary growth phase with aeration showed the ability to accumulate phenolic compounds and ascorbic acid in amounts up to 0.32 mg g-1 and 0.19 mg g-1. The 74-day-old cultures had the highest contents of retinol (0.16 mg g-1) and α-tocopherol (0.68 mg g-1). Growth in nitrogen- and phosphorus-depleted media increased catalase and superoxide dismutase activity. A comprehensive analysis of all data showed that the antioxidant defence system is stress-resistant and flexible under varying aeration conditions and nitrogen and phosphorus availabilities. Thus, the strain CAMU MZ-Ch4 can be considered a potential producer of lipids, pigments, proteins, and vitamins under various culturing conditions.

Use of mining effluents for the production of algal-based colorants

In this research, a mining effluent was used to produce microalgal and cyanobacterial biomass to obtain red (carotenoids) and blue pigments (phycocyanin). Two strains were isolated from a hydrothermal source in Norte de Santander and grown in mining wastewater mixed with 50% BG-11 medium for the Osci_UFPS01 cyanobacterium and 50% with Bold Basal medium for the Chlo_UFPS01 microalgae. A carbon, nitrogen, and phosphorus experiment design was developed, and subsequent response surface analysis (RSM) was used to determine the optimal operating conditions for the formation of the products of interest. A notable decrease in pigment production was observed compared to that in the controls without mining wastewater. Overall, 45% of phycocyanin (C PC) per unit dry weight (DW) and 1,129% (w/w) of carotenoids were obtained in the cultures with a mining wastewater mixture in the final optimization processes.

Leveraging the dynamics of microalgal CO2 capture to estimate the maximum inherent photosynthetic potential

AbstractBACKGROUNDNatural photosynthesis, utilizing intelligent molecular machinery to harness sunlight, stands as the benchmark for efficient energy generation. Despite its high quantum efficiency compared to synthetic methods, challenges persist due to dynamic nutritional and light requirements in plant, microalgae, and cyanobacteria‐driven processes. Reported microalgae CO2 uptake rates rely on biomass dry cell weight measurement after certain incubation period and systematic study of required CO2 concentrations for optimal photobioreactor operation remaining unexplored. This research is thus aimed at evaluating the critical dissolved CO2 (Ccrit ∙ CO2) concentration and specific CO2 uptake rates (SCUR) of Chlorella minutissima (CM) culture in the presence of surplus light and other nutrients by online monitoring and measuring the dynamic CO2 uptake rates which will help in maintaining the optimal rate of CO2 delivery for continuous cultivation of microalgae while minimizing the escape of CO2.RESULTSDissolved Ccrit ∙ CO2 was determined to be in the range of 16–20 mg/L, and the maximum SCUR in BBM (Bold Basal Medium) was found to be 0.73 mg CO2 (mg dcw ∙ h)−1. Interestingly, this SCUR value is nearly three times greater than that of the most efficient in vitro artificial photosynthetic novel pathway reported so far.CONCLUSIONFrom the calculated SCUR values, it may be noted that 9.6 g of biomass can be obtained from 1 g of microalgal inoculum in a day, thereby setting a benchmark for the scientists working in the areas of bioprocess engineering, synthetic biology, and metabolic engineering to comply. © 2024 Society of Chemical Industry (SCI).

From waste to resource: Effects of digested rotten potato supernatant on the growth, total biomass and nutrient composition of Chlorella vulgaris

A study was carried out to evaluate the growth performance of Chlorella vulgaris, a green microalga, in three different concentrations of digested rotten potato supernatant (DRPS) for 16 days. C. vulgaris was grown in 20 % (T1), 40 % (T2), and 60 % (T3) of the DRPS and at the same time in Bold Basal Medium (BBM) as a control (T4). A significantly highest cell density of C. vulgaris was found in T1 (192.83 ± 1.75 × 105 cells mL−1) in comparison to T2 (136.83 ± 5.58 × 105 cells mL−1), and T3 (99.11 ± 5.38 × 105 cells mL−1) (p < 0.001 for all comparisons) while the cell density at T1 (192.83 ± 1.75 × 105 cells mL−1) and T4 (180.907 ± 4.58 × 105 cells mL−1) did not differ significantly (p = 0.227). Moreover, the mean daily division rate of C. vulgaris was significantly higher in T1 (0.340 ± 0.001 divisions day−1) in comparison to other concentrations of DRPS (p < 0.001 for all comparisons). The maximum value of total biomass (1.07 ± 0.10 g L−1) was found in T1 which was statistically similar to those in T4 and T2. In addition, there was no significant difference between the mean maximum values of chlorophyll-a content and optical density of C. vulgaris in T1 and T4. The highest protein content of 42.67 ± 0.57 % was observed in T4 which was significantly higher than T1 (39.43 ± 1.67 %) (p = 0.027). It is also worth mentioning that there was no significant difference in the crude lipid content of the microalgae grown in T1 (10.06 ± 0.17 %) and T4 (9.88 ± 0.14 %) (p = 0.616). Hence, 20 % DRPS can be used as an alternative culture media of BBM for C. vulgaris with a broad aim to accelerate the sustainable advancement of microalgal production.

The impact of printing industry effluent on the growth and antioxidant response of the freshwater green microalga Chlorella sorokiniana

Contamination of aquatic ecosystems with printing industry wastewater is a serious concern because of the toxicity associated with the effluent components and a tendency to create cascading ecological effects. The influence of printing-press effluent on the freshwater microalga Chlorella sorokiniana strain UTEX2714 was studied under controlled laboratory conditions. The microalga was subjected to various effluent concentrations prepared by diluting printing-press effluent with bold basal medium (BBM) in the following ratios (effluent:medium): 1:149, 1:119, 1:99, 5:95 and 10:90, reflecting greater concentrations of the effluent. The control BBM had no effluent added. Higher effluent concentrations had a negative impact on the cell density of C. sorokiniana; at low effluent concentrations the algae displayed a high growth rate and high chlorophyll a production (p < 0.05), although total chlorophyll content did not differ significantly among treatments (p ≥ 0.05). This study also discovered an increase in peroxidase activity in this microalga in response to higher concentrations of printing-press effluent, which indicated an increase in oxidative stress that prompted antioxidant defence mechanisms. We conclude that printing-press effluent adversely affects the physiology of C. sorokiniana, indicating the potential of printing wastewater to harm phytoplankton in freshwater environments.

Biofloc wastewater for microalgae (Chlorella ellipsoidea) production: an approach to algal biomass production and nutrient remediation

ABSTRACT Bold Basal Medium (BBM) is a standard but expensive medium for Chlorella ellipsoidea culture. This study evaluated the effect of biofloc wastewater (BWW) on the growth and pigment content of C. ellipsoidea and also investigated its bioremediation potential. The experiment was conducted for 24 d in five treatments, each with three replications. BBM was replaced with BWW at 0, 25, 50, 75, and 100% levels and considered as control (0% BWW), 25% BWW, 50% BWW, 75% BWW, and 100% BWW treatment, respectively. During the exponential period, the cell dry weight, optical density, cell density, specific growth rate, chlorophyll a, b, and β-carotene content were significantly (P ˂ 0.05) higher in 75% BWW treatment, which was followed by 0% BWW, 50% BWW, 100% BWW, and 25% BWW, correspondingly. NH3, NO2, and PO4 recovery efficiency were also higher in 75% BWW treatment. Therefore, the study proves that 75% BWW has the potential to culture C. ellipsoidea as an alternative to expensive BBM along with nutrient recovery from BWW.

Growth performance and heavy metal analysis of Oreochromis niloticus fed with phycoremediate microalgae supplemented diet formulation

The rising demand for fish as the primary protein source for human consumption is a continuous challenge to meet. Modern-day studies have exploited microalgae as an alternative plant-protein source to replace fishmeal. However, it is critical to protect the fish culture from toxic metal accumulation, which is dangerous to both the organisms and consumers. Hence, this research aimed to study the effects of using microalgae bioproducts on the growth performance and heavy metal accumulation in the muscle tissue of Oreochromis niloticus. In this study, 2% of Scenedesmus sp. cultivated in Bold Basal Medium and wet market wastewater was partially substituted to replace fishmeal. The physicochemical properties of formulated feed were analyzed and compared between control, formulation 1 and formulation 2. The fish were cultured for 12 weeks, and their weight gain was monitored weekly using an analytical balance. The muscle tissue samples were collected and digested using 37% HCl and 65% HNO₃. As a result, the growth performance of the fish in formulations 1 and 2 showed a positive trend and a higher average growth rate of up to 43.38 and 44.85 g, respectively. The effect of seven heavy metals, such as zinc, iron, copper, lead, mercury, manganese, and cadmium, on the fish was analyzed using the Inductive Coupled Plasma Mass Spectrometry (ICPMS) technique. An analysis of variance indicated a significant difference (p &lt; 0.05) for zinc, copper, iron, lead, and mercury concentrations but not for manganese and cadmium (p &gt; 0.05). It can be deduced that the inclusion of 2% Scenedesmus sp. in the diet formulation results in a minor variation in fish growth performance. However, this could contribute to maintaining and improving the growth rate of O. niloticus and the concentration of heavy metals in their muscle tissue. Continuous examination of heavy metal accumulation in fish is necessary to ensure the safeness and nutritional quality are adequate for human consumption.

Boosting Antioxidant Activity and Phenolic Content in Scenedesmus dimorphus

Scenedesmus dimorphus, a microalgae from the Chlorophyceae class, possesses compounds with antioxidant potential. This study focuses on determining the antioxidant activity of the methanol extract of *Scenedesmus dimorphus* cultured in Bold Basal Medium (BBM) with NaCl concentrations of 10 g/L, 12.5 g/L, and 15 g/L. NaCl was added after 3, 6, and 9 days of cultivation to evaluate the impact on antioxidant activity. The antioxidant activity was assessed using the DPPH (1,1-diphenyl-2- picrylhydrazyl) assay. The results showed that the highest antioxidant activity occurred in cultures with 15 g/L NaCl, with DPPH inhibition of 13.71% and a biomass yield of 0.1914 g in 500 mL of medium. The microalgae demonstrated the ability to withstand NaCl stress, showing improved antioxidant activity over time. On day 9, with the addition of 15 g/L NaCl, the antioxidant activity increased to 26.82%, the IC50 value was 183.63 mg/L, and the biomass weight reached 0.2568 g in 500 mL of medium. Additionally, the total phenolic content increased to 70.10 mg GAE/g extract on day 9. These findings suggest that NaCl stress at specific intervals enhances both antioxidant activity and phenolic content in Scenedesmus dimorphus.

Investigation of the influence of microalgal culture medium on biomass production

Microalgae have been shown to produce a variety of products, including biofuels, proteins, and beta-carotene. However,increasing their biomass production still requires a lot of effort from researchers. Biomass from different culture media has presented challenges and possible solutions to improve microalgae production efficiency. In addition to factors such as light and temperature, nutrients also affect microalgal culture media. This study has developed basic experiments revolving around the fluctuations of essential nutrients such as carbon (C), nitrogen (N), phosphorus (P) during the cultivation ofChlorella vulgaris on Bold’s Basal Medium (BBM). As a result, reducing or increasing the N and P concentrations by half,and replacing C in NaHCO3 with glucose significantly changed the growth curve of C. vulgaris. There were significant fluctuations in the microalgal characteristics of the lag phase and the stable phase, with the former being longer and the latter being shorter compared to BBM. Additionally, the maximum biomass obtained was 1.95 g/L dry weight when microalgae were cultivated in medium containing glucose (M1), where the C concentration was replaced by glucose, and 1.56 g/L when the P content was increased 1.5 times compared to 1.35 g/L of dry weight in BBM. However, reducing or increasing nitrogen content by half inhibited cell growth, leading to low biomass efficiency of only 1.07 g/L and 1.21 g/L, respectively. On the other hand, changes in the essential nutritional composition of the culture medium also affected the efficiency of settling of C. vulgaris, this value was higher than 80% in all media compared to BBM.

Fatty Acids Profiling from An Antarctic Microalga, Pseudococcomyxa sp.

The main source of valuable fatty acids such as eicosapentaenic acid (EPA) and docosahexaenoic acid (DHA) that are important for human health are from marine fish. However, fatty acids derived from fish have many downsides such as contaminated with environmental pollution. Plus, the marine fish sources are limited due to several reasons. Hence, microalgae are seen to be potential alternative source of these valuable fatty acids. Microalgae are equipped with distinctive adaptive mechanisms that allow them to survive in all sorts of habitat even in subzero temperature such as in Antarctic. One of them is increased in their fatty acid levels. This research aims to characterize one species of Antarctic microalga isolated from polar ice of genus thought to be Pseudococcomyxa sp. and to profile its fatty acid compositions. The fatty acid methyl ester (FAME) was profiled using gas chromatography mass spectrometer (GC-MS) using methanol as solvent. Generally, the morphological characteristics of possible genus of Pseudococcomyxa sp. matched the actual Pseudococcomyxa sp. The total fatty acids percentage in Pseudococcomyxa sp. cultured in Bold’s Basal Medium (BBM) had been successfully identified using methanol as solvent which is 53.13% with linolelaidic acid as the highest percentage (27.15%). The fatty acid compositions of Antarctic microalga, Pseudococcomyxa sp. which were successfully profiled have many potentials to be exploited in the future especially in pharmaceutical and food industry. Keywords: Antarctic, fatty acids, food, microalgae, pharmaceutical

Growth strategies of Chlorella vulgaris in seawater for a high production of biomass and lipids suitable for biodiesel

Chlorella vulgaris is a freshwater microalga that synthesises large amounts of saturated lipids, which makes it suitable for production of bioenergy and biofuels. Since its cultivation usually requires freshwater, it competes with agriculture, economic development and ecological conservation for this limited natural resource. This study investigated the possibility of the partial replacement of freshwater by seawater (50 %) in the growth medium for a more sustainable biomass and lipid production. Chlorella vulgaris 211-11b was cultivated as shake-flask cultures in Bold's Basal Medium (BBM) formulated with 50 % freshwater and 50 % seawater under photoautotrophic, mixotrophic and heterotrophic conditions for eight days with glucose as organic carbon source in the latter two cases. The alga's best growth performance and highest lipid contents (49 % DW−1), dominated by palmitioleic and oleic acid, occurred under mixotrophic rather than photoautotrophic and heterotrophic conditions. This study demonstrates a more economic and ecologically sustainable biomass and lipid production of C. vulgaris by saving 50 % freshwater, which is available for other purposes.

A multifunctional cellulose- and starch-based composite hydrogel with iron-modified biochar particles for enhancing microalgae growth

A multifunctional polysaccharide-based hydrogel was studied as an additive for enhancing microalgae growth. The hydrogel was fabricated by physically and chemically crosslinking renewable ingredients of carboxymethyl cellulose (CMC), arrowroot starch, and activated biochar modified with iron using a bio-crosslinker of oxidized sucrose and a plasticizer of glycerol. The optimum formula for the hydrogel with a high swelling ratio, BET surface area, and electrical conductivity was found to include 1 g starch, 3 g CMC, 1.5 g biochar, 15 mL oxidized sucrose, and 1.5 mL glycerol in 200 mL deionized water. The algal yield and cell concentration after 14 days of growth in a Bold basal medium with an optimum concentration of 2.5 g hydrogel/L increased by 65.7 % and 92.2 %, respectively, compared to those of the control without the hydrogel. However, if the hydrogel concentration in the culture increased to 12.5 g/L, the algal yield was decreased by 67.8 % compared to the control due to oxidative injury. The hydrogel additive could significantly increase the nitrogen but decrease the carbon, hydrogen, and sulfur contents of the microalgae. The algal yield with 2.5 g/L hydrogel additive improved by 13.9 % compared to the algal yield with the same amounts of individual non–crosslinked hydrogel ingredients.

Growth Performance and Biochemical Composition of Desmodesmus sp. Green Alga Grown on Agricultural Industries Waste (Cheese Whey)

Agricultural industries produce vast amounts of liquid waste, which contains a significant concentration of nutrients. In the context of emphasizing the huge increase in population, climate changes, and pollution which results in depletion of fresh water resources, a sustainable solution for a greener future is needed. Wastewater treatment by the use of microalgae can mitigate a part of the problem by restoring water for irrigating agricultural crops. Little studies give insights on the physiological responses and ultrastructure of the Chlorophyta alga Desmodesmus sp. as it grows in cheese whey (CW). The algal strain was mixotrophically grown in a growth medium composed of CW only and CW supported with Bold’s basal medium (BBM) for 14 days. The potent response was observed with algal cultures fed by 15% CW enriched with 50% BBM. Fifteen percent CW in combination with 50% BBM significantly improved Desmodesmus sp. growth (303%), productivity (325%), and accumulation of cell metabolites, mainly lipids (3.89%), and carbohydrates (1.95%). On the contrary, protein and photosynthetic pigment (chlorophyll a, chlorophyll b, and carotenoids) contents were higher in BBM than in all treatments. Fatty acid composition demonstrated that the predominantly accumulated fatty acids were palmitic (25.86%), oleic (35.31%), and linoleic acid (13.22%). In conclusion, Desmodesmus sp. can be a good candidate for phycoremediation when cultivated on CW, whereas it can reduce the nutrition costs and water demand of algal cultivation by 50% and 15%, respectively. Therefore, it may be an effective strategy for algal mass production in sustainable agricultural systems.

Unlocking the potential of Chlamydomonas sp. for sustainable nutrient removal from POME: A biokinetic investigation

This study aimed to assess the capability of Chlamydomonas sp., for the treatment of palm oil mill effluent (POME), with a particular focus on nutrient removal efficacy. Batch cultivation experiments were conducted using Chlamydomonas sp. in bold basal medium (BBM) with varying POME concentrations. Biokinetic coefficients for nutrient removal were determined using the Michaelis-Menten equation. Over 16 days, Chlamydomonas sp. efficiently removed 100 % of ammonium (NH4+) and nitrate (NO3−), 66–89 % of phosphate (PO43−), and 16.7–33.2 % of chemical oxygen demand (COD). Experimental results and biokinetic coefficients highlighted the superior removal of NH4+ and PO43− by Chlamydomonas sp. in POME. For NH4+, the determined coefficients were k = 3.7161 mg NH4+ mg−1 DCW d−1, Km = 217.97 mg L−1, YN = 17.64 mg DCW mg−1 NH4+. For PO43−, the coefficients were k = 2.5413 mg PO43− mg−1 DCW d−1, Km = 131.53 mg L−1, YP = 12.91 mg DCW mg−1 PO43−. Chlamydomonas sp. biomass performed exceptionally well under low NH4+ and PO43− concentrations, requiring minimal nutrient input compared to COD and NO3−. In conclusion, Chlamydomonas sp. shows promise as an efficient and sustainable option for nutrient removal from POME and other wastewater sources, particularly those containing high levels of nitrogen and phosphate.

Analysis of the growth profile, biochemical composition and nutrient removal efficacy of Spirulina sp. NCIM 5143

In the present manuscript, the growth profile of the microalgae Spirulina sp. NCIM 5143 was studied. Screening was performed on four commercial media, i.e., blue‒green-11 (BG-11), Bold’s basal medium (BBM), algal culture medium (ACM), Zarrouk’s medium (ZM), and different concentrations (20%, 40%, 60%, 80%, and 100%) of unsterilized dairy effluent (UDE). Characterization of biomass was performed to assess its biochemical composition through various assays. Elemental composition and bioactive compound analysis were accomplished by inductively coupled plasma-atomic emission spectroscopy (ICP‒AES) and gas chromatography‒mass spectrometry (GC‒MS), respectively. The results revealed that maximum values of most of the parameters, i.e., optical density (0.21), chlorophyll (2.00 mg/l), proteins (119.17 mg/l), and wet (4.06 g/l) and dry biomass weight (0.28 g/l), were found on ZM. For UDE, maximum growth parameters and the highest nutrient removal efficiency were obtained at 100% concentration. Biochemical analysis revealed that total Kjeldahl nitrogen (7.14±0.49%), crude protein (48.23± 3.34%), total antioxidant activity (3.07±0.03 mg AAE/g), and total phenols (8.88±1.93 mg GAE/g) were present in the biomass. Elemental and GC‒MS analysis detected essential micronutrients and many bioactive compounds, respectively. Hence, this study proved that Spirulina sp. NCIM 5143 has the potential for the management of waste dairy effluent. This study also showed its cost-effectiveness, as the dairy effluent analyzed is used without any kind of sterilization. In addition, its biomass is rich in several essential elements, antioxidants, and bioactive compounds of therapeutic and nutraceutical importance.