Algal Inoculation Research Articles

Characteristics of algal-bacterial aerobic granular sludge treating real wastewater: Effects of algal inoculation and alginate-like exopolymers recovery

Limited information is available on the characteristics of algal-bacterial aerobic granular sludge (AGS) treating real wastewater, especially on its alginate-like exopolymers (ALE) production. In addition, the effect of target microalgae species inoculation on the system performance has not been fully understood. This study aimed to reveal the effect of microalgae inoculation on the characteristics of algal-bacterial AGS and its ALE production potential. Two photo-sequencing batch reactors (PSBR) were employed, namely R1 with activated sludge and R2 with Tetradesmus sp. and activated sludge being inoculated, respectively. Both reactors were fed with locally sourced municipal wastewater and operated for 90 days. Algal-bacterial AGS were successfully cultivated in both reactors. No significant difference was observed between the performances of R1 and R2, reflecting that the inoculation of target microalgae species may not be crucial for the development of algal-bacterial AGS when treating real wastewater. Both reactors achieved an ALE yield of about 70 mg/g of volatile suspended solids (VSS), indicating that a substantial amount of biopolymer can be recovered from wastewater. Interestingly, boron was detected in all the ALE samples, which might contribute to granulation and interspecies quorum sensing. The enrichment of lipids content in ALE from algal-bacterial AGS treating real wastewater reveals its high resource recovery potential. Overall, the algal-bacterial AGS system is a promising biotechnology for simultaneous municipal wastewater treatment and resource (like ALE) recovery.

Investigation of microalgal treatment for poultry slaughterhouse wastewater after the dissolved air flotation unit

Meat and meat products are some of the primary consumption products required for the continuation of life. The world population accessed over 7.5 billion that means the demand for food is increasing every day. Slaughterhouses and integrated meat facilities are being rapidly developed and established to meet meat and meat product requirements. In slaughterhouse poultry plants, high amounts of water are utilized for the meatpacking process. The poultry slaughterhouse wastewaters contain high levels of organic solids such as fat, blood, suspended matter, and dissolved protein, which can be treated using physical, chemical, and biological treatment methods. In this study, the treatment of poultry slaughterhouse wastewater preliminarily treated by dissolved air flotation, with microalgae culture (Chlorella Vulgaris) development, unlike traditional treatments, was investigated. Chemical oxygen demand and total suspended solids parameters for wastewater treatment have been monitored for 15 days of incubation. 0.8, 4, 8, 12, and 20% by volume algae were applied for slaughterhouse wastewater, and the optimum amount of algal inoculation was determined after 15 days. When the removal efficiencies were examined, the most appropriate amount of inoculation rate with 76 % chemical oxygen demand removal and 87% algal growth (as total suspended solids) was selected as 12%.

Membrane filtration of manganese (II) remediated-microalgae: Manganese (II) removal, extracellular organic matter, and membrane fouling

This study investigated the biosorption efficiency of Mn (II) by algae (Thalassiosira pseudonana) and membrane performance in a hybrid algae-membrane system. The presence of Mn (II) at 2–10 mM could influence (i.e., at lower algal inoculation ratio of OD = 0.1) or showed negligible effect (i.e., at higher inoculation ratio of OD = 0.17), on algal growth, cell morphology, pigment content, and extracellular organic matter production. The Mn (II) removal was mainly attributed to the algal uptake mechanisms; and higher removal efficiency (>66%) was achieved at higher algal inoculation ratio. Although increasing the Mn (II) concentration could reduce the algal uptake ratio of Mn (II), the membrane performance was improved. The optical coherence tomography (OCT) analysis revealed that the specific volume of cake layer increased gradually over time, however, the irreversible fouling was predominant and associated the presence of building blocks in soluble organics.

Effect of Algal Inoculation on COD and Nitrogen Removal, and Indigenous Bacterial Dynamics in Municipal Wastewater.

The effects of algal inoculation on chemical oxygen demand (COD) and total nitrogen (TN) removal, and indigenous bacterial dynamics were investigated in municipal wastewater. Experiments were conducted with municipal wastewater inoculated with either Chlorella vulgaris AG10032, Selenastrum gracile UTEX 325, or Scenedesmus quadricauda AG 10308. C. vulgaris and S. gracile as fast growing algae in municipal wastewater, performed high COD and TN removal in contrast to Sc. quadricauda. The indigenous bacterial dynamics revealed by 16S rRNA gene amplification showed different bacterial shifts in response to different algal inoculations. The dominant bacterial genera of either algal case were characterized as heterotrophic nitrifying bacteria. Our results suggest that selection of indigenous bacteria that symbiotically interact with algal species is important for better performance of wastewater treatment.

An efficient and reproducible method for improving growth of a soil alga (Chlorococcum infusionum) for toxicity assays

This study evaluated five methods of soil inoculation using the soil alga Chlorococcum infusionum to determine the most efficient and reproducible method for promoting the growth of soil algae for toxicity testing. The five techniques included application of C. infusionum in a circle on top of the soil, to a central spot on top of the soil, to a central spot in the subsoil, to one side on top of the soil, and application divided between a circle and a central spot on top of the soil. Of these, the first method generated the greatest amount of chlorophyll fluorescence and was the method with the best reproducibility. We evaluated the applicability of this method in an assessment of the toxicity of copper and nickel to C. infusionum in two representative standard soils. Copper (20–75mg/kg for OECD soil and 20–60mg/kg Lufa 2.2 soil) and nickel (400–500mg/kg for OECD soil and 60–100mg/kg Lufa 2.2 soil) reduced the chlorophyll fluorescence of C. infusionum when the inoculation was delivered in a circle on top of both soil types. To our knowledge, this is the first study to assess the suitability of different soil algal inoculation methods for terrestrial toxicity testing.

Cyanobacteria, pesticides and rice interaction

Cyanobacteria (blue-green algae) are widely distributed in tropical wet land rice fields where they play important role in building soil fertility. Due to their ability to photosynthesize and fixing atmospheric nitrogen, these are used as inoculants in rice fields to obtain additional benefits. The fertilizers and pesticides are being extensively used and therefore, it is necessary to find out effects of agrochemicals particularly pesticides on non target organisms like cyanobacteria. In the present investigation interaction of pesticides and cyanobacteria has been studied at different stages of rice crop. It was observed that application of herbicide butachlor decreased growth and N2-fixation of both native and inoculated cyanobacteria whereas insecticide metacid application was found to increase these attributes. The interaction of algal inoculation and both the biocides application were superior than algal inoculation with the herbicide application on both algae and rice. It is concluded from this study that herbicides application affected adversely cyanobacteria but insecticide application was favorable to them and application of both biocides was better than herbicide alone. Therefore judicious use of these chemicals and cyanobacteria in rice fields are suggested.

TOXICIDADE DE SOLO DE “LANDFARMING” DE REFINARIA DE PETRÓLEO TRATADO COM ALGAS PARA A MINHOCA Eisenia fetida

A toxicidade para a minhoca Eisenia fetida de amostras de solo de landfarming de refinaria de petróleo foi avaliada em solo inoculado com comunidades de algas alóctones isoladas de solo limpo. Amostras do solo de landfarming da Refinaria de Petróleo de Paulínia (REPLAN/PETROBRAS) foram mantidas sob saturação hídrica em bandejas plásticas, em Casa de Vegetação, durante 180 dias e submetidas à inoculação algal, incorporação e remoção do crescimento algal visível. Decorridos 30 dias da inoculação, os membros das comunidades com crescimento ativo no início da colonização foram identificados ao nível gênero: Anabaena, Chroococcus, Scytonema e Lyngbya (Cyanophyta), Klebsormidium, Mougeotia e Oedogonium (Chlorophyta) e Navicula (Bacillariophyta). A toxicidade para E. fetida foi avaliada em amostras do solo de landfarming selecionadas ao acaso. Não sendo observado o efeito agudo, o efeito na biomassa de espécimes adultos da minhoca foi avaliado, indicando destoxicação do solo de landfarming quando submetido à remoção do crescimento algal visível, após 180 dias da inoculação. Os resultados deste estudo indicam que efeitos subletais na biomassa da minhoca E. fetida são capazes de fornecer medidas efetivas para o monitoramento da toxicidade do solo durante o processo de remediação.

Effect of blue green algae, nitrogen levels and modified urea materials on yield attributes and yield of wetland rice (Oryza sativa)

A field experiment was carried out during the rainy season (July-October) of 1990 and 1991 at New Q cwhi, to study the combined effect of slow-release nitrogen fertilizers and blue green algae on the gram and .,!raw yields of rice (Orym sntivn L.). The application of urea supergranules and dlcyandiamide-coated urea at 80 kg Nlha resulted a nitrogen economy of 21 ar~d 24 kg Nlha respectively in rice with algal inoculation and 38 and 44 kg N!ha respectively without d g d inoculation.

Seasonal development of algal biomass in snow-covered fast ice and the underlying platelet layer in the Weddell Sea, Antarctica

The seasonal changes of the nutrient regime and the development of algal communities in snow-covered fast ice and the underlying platelet layer was investigated in the eastern Weddell Sea during autumn, winter, and spring 1995. In the upper sea ice, an autumnal diatom community became enclosed during subsequent ice growth in winter, declined, and was replaced by a flagellate dominated community in spring. In this layer, nitrate was completely exhausted at the end of spring, although nutrients had been partly regenerated in early spring. The progressive congelation of platelet ice contributed significantly to sea ice growth thus influencing algal inoculation of the sea ice bottom. Biomass, present in the uppermost section of the platelet layer, could be found in the sea ice bottom after this section congealed to solid ice. After incorporation, species composition changed from larger and chain-forming species to species of smaller cell size. Concurrently, net growth rate slowed down from 0.07 day−1 within the platelet layer to 0.03 day−1 within the sea ice. Despite a thick snow cover of more than 20 cm, maximum biomass yield was 210 mg chl a m−2 in the platelet layer and 40 mg chl a m−2 in the sea ice respectively, while 95% of the latter was located within consolidated platelet ice. Total fast ice biomass observed here is significantly lower than that observed in snow-free fast ice of the Ross Sea, but because snow cover of the southern Weddell Sea is representative of most fast ice areas in the Antarctic, the data presented here are of general value.

The use of biofertilizer of Calothrix sp. M103, enhanced by addition of iron and siderophore production

Calothrix sp. M103, enhanced by addition of iron and siderophore production was used as a biofertilizer. The strain was isolated from a colony on the surface root of a rice plant from a rice field in Bangladesh. It showed a marked and immediate increase in nitrogenase activity in response to the addition of iron and also a normal activity (compared with the control) under siderophore production. The addition of iron to iron-limited cultures resulted in a rapid increase in algal iron (11-fold) followed by a marked increase (9-fold) in nitrogenase activity, reaching about 11.8 kg N/ha/crop. This was more than twice the amount of nitrogen usually fixed by the alga during normal growth (controlled conditions), suggesting that pulsing algal inocula with iron would increase the efficiency of algae as a biofertilizer. Indeed, the use of an iron-pulsed inoculum of this strain as a biofertilizer resulted in an increase in the yield of sweetcorn by ca 143% over that produced by the control (no algal inoculation) and to ca a 73% increase over that produced by the normal inoculum (unpulsed with iron). The ability of this strain to produce siderophores has also led to both normal (compared with the control) nitrogenase activity as well as normal growth, which shows a marked contrast to other circumstances where the non-siderophore producing strains showed no growth at all. The significance of these observations on the enhancement of biofertilizer technology is discussed.

EFFECT OF FERTILIZER NITROGEN AND ALGAL INOCULATION ON RICE CROP

Application of 60 kg N/ha through tertilizer nitrogen with blue green algal in- oculation was batter than 60 kg N/ha with no blue green algal inoculation, both in torms of total production and net profit. Treatment 60 kg N/ha plus inoculation with blue green algae gave the highest grain yield of rice (4.05 t/ha) and also. a maximum net profit of Rs. 917.00. The highest content of total N in plants at the panicle initiation stage and crude protein content in paddy grain were also recorded under 60 kg N/ha with blue green algal inoculation.

Effect of grazer regulation and algal inoculation on photodependent nitrogen fixation in a wetland rice field

A dry season field experiment conducted for two consecutive years highlighted problems of achieving increased populations of N2-fixing blue-green algae (BGA) in wetland rice fields. Inoculation of non-indigenous BGA strains, either dried or as fresh viable inocula even at high levels of application, was unsuccessful. A limiting effect of grazing invertebrate populations on BGA establishment was evident, but other factors were involved. Reducing grazer pressure did not permit establishment of inoculated BGA; interspecific competition and environmental factors may explain the inoculation failure. Grazer regulation permitted the establishment of a fast-growing indigenous N2-fixing Anabaena and the doubling of N2-fixing activity over a control. Neither inoculation nor grazer control affected grain yields significantly.

Effect of algal inoculation on the yield and vitamin C content of two varieties of tomato

Two varieties of tomato (Pusa Rubi and Selection 120) positively responded to algal inoculation in terms of the yield of fruits and shoots, but there was no significant effect on the vitamin C content of the fruits. A combined application of urea and algae was more effective than the application of urea alone.

Influence of blue green algal inoculation on the crop yield of rice plants

Abstract Increased paddy yields due to algal inoculation were earlier reported in controlled pot and field experiments (1–8). The present communication deals with a field trial conducted in a cultivator's field at Vasudevanallur in Madras State, during November 1966 to March 1967, with ASD 5 paddy variety. The paddy cultivation in the field followed a groundnut crop.

Preliminary observations on the interaction of different rice soil types to inoculation of blue-green algae in relation to rice culture

The results of investigation with soils of seven different regions of India for testing their suitability for the nitrogen enrichment of them using the bluegreen algae are dealt with. Of the soils studied (of Karjat, Palur, Pattambi, Kayamkulam, Nellore, Nagenahalli and Titabar) those of Nellore, Nagenahalli and Titabar were the best as regards their response to algal inoculation as well as yield potential. Results also indicated that apart from nitrogen supply, the algae contribute certain other growth promoters beneficial to the rice crop. Studies on the physical and chemical properties of the soil before planting do not apparently disclose any limiting factor for growth of the rice plant or algae, but the performance of both in the soils indicate that some essential organic substance/s or trace elements could be the limiting factor/s.

EFFECT OF NITROGEN-FIXING BLUE-GREEN ALGA: TOLYPOTHRIX TENUIS ON THE NITROGENOUS FERTILITY OF PADDY SOIL AND ON THE CROP YIELD OF RICE PLANT

(1) The effect of inoculating the paddy field with nitrogen-fixing blue-green alga: Tolypothrix tenuis upon the yield of rice plant was investigated at nine experimental farms located in various districts through Japan. (2) The experiments conducted during five successive years showed that the amount of ammonification was higher in inoculated soils than in non-inoculated ones.(3) On an average the increase of rice crop obtained by inoculating the alga in relatively nitrogen-poor paddy fields was: 2.0% in the first year, 8.0% in the second year, 15.1% in the third year, 19.5% in the fourth year and 10.6% in the fifth year.(4) The fact that the favorable effect of algal inoculation increased year by year may be attributed to the accumulation in the paddy field of the algal cells which would be partially decomposed and partially remain and proliferate in the following years to increase, at any rate, the nitrogenous fertility of the paddy soil.