Heterotrophic bacteria attached to seaweeds

Viable counts of heterotrophic bacteria attached to the green algae, Monostroma nitidum Wittrock and Enteromorpha linza (Linné) J. Agardh, ranged from 10⁴ to 10⁶/cm², and those attached to the red alga Porphyra suborbiculata Kjellman from 10³ to 10⁴/cm². These bacterial populations were larger than those attached to the brown alga Eisenia bicyclis (Kjellman) setchell ranging from 10¹ to 10⁴/cm². The bacterial populations in the environmental sea water. Nabem Inlet and Otsuchi Bay (Japan), were 10³/ml. Orange and yellow pigmented bacteria were predominant on the green and red algae, but not in the bacterial populations of the brown alga and the sea water. Most of the pigmented bacteria were identified as belonging to the Flavobacterium-Cytophaga group. A beneficial relationship was suggested between the green algae and the pigmented bacteria. Proportions of Vibrionaceae were small on the green algae.     

Biomechanical properties and holdfast morphology of coenocytic algae (Halimedales, Chlorophyta) in Bocas del Toro, Panama

For attached marine organisms, specific biomechanical properties may result in detachment or in tissue loss, when sufficient tensile force is applied. Algae experience such forces through water movement, which may thus act to limit size, abundance, and species composition, of populations of algae.Coenocytic construction is uncommon in the algae, but it occurs relatively more frequently in green algae found in shallow subtidal sediments associated with coral reefs, e.g., at our study site of Isla Colon, Bocas del Toro, Panama. We studied the biomechanical properties of some tropical coenocytic algae (Udotea flabellum (Ellis et Solander) Lamouroux, Penicillus capitatus Lamarck, P. pyriformis A. and E.S. Gepp, and Halimeda gracilis Harvey) anchored in sediments. We compare our results with published data on other coenocytic algae, as well as with multicellular algae. Our results show that properties of sand-dwelling coenocytes, such as mean force to dislodge (4.9-12.7 N), mean force to break (6.6-22.1 N), and mean strength (1.0-7.0 MN m^− 2), are all within the range reported for temperate, multicellular, algae. In contrast, the coenocytes differed markedly from the temperate non-coenocytes in the consequences of applied tensile force: coenocytes were removed whole, while most temperate algae attached to rocks break within the thallus. Some multicellular algae can regrow from tissue left on the substratum; three of the four coenocytic species we examined had rhizoids connecting closely adjacent (0.1-0.15 m) individuals, and these rhizoids may serve to regrow a new individual. While our experiments indicated that sufficient tensile force results in dislodgment, calculations using the experimentally determined variables led us to conclude that water velocities sufficient to dislodge individuals are unlikely to occur. Since dislodgment is usually fatal for algae, the role of the holdfast is a critical one. All of the species we investigated had similar holdfast morphology, a mass of rhizoids which entrained sand, the entire unit forming a hemispherical to cylindrical mass. Despite the consistency in holdfast form, and the initial prediction that this was an optimal form for anchoring these algae, our data suggest that this is not the case.     

Direct observations on the sublittoral marine algae of Argyll,Scotland

Summary The distribution with depth of sublittoral marine algae has been investigated at 11 sites on the west coast of Scotland. More than half of the species found were confined to the sublittoral zone. The greatest variety of species was found in shallow water at sites sheltered from excessive turbulence. With increasing depth the number of species found steadily decreased. There was no evidence of a specifically distinct algal flora confined to deeper water. No algae were found deeper than 36 m below ELWS at any site, but the lower limit of algal growth was reduced to 9 m in a turbid water loch and to 3 m at a site where the herbivorous echinoderm Ophiocomina nigra was abundant. Fairly distinct algal communities were found on different substrates. The major communities recognised underwater were algae attached to stable substrata, algae attached to unstable substrata and epiphytic on other algae, especially on the stipes of Laminaria hyperborea. On stable rock in areas subject to water movement L. hyperborea forest was the dominant vegetation whereas on unstable substrata and in sheltered localities L. saccharina was dominant.     

三峡水库神农溪2014年春季浮游藻类演替成因分析

摘要：【目的】研究三峡水库神农溪库湾春季水华期间浮游藻类演替及其成因分析。【方法】2014年3–5月在神农溪库湾布置了6个断面(SN01–SN06),在神农溪汇入长江干流河口附近水域设置1个断面CJBD,对浮游藻类、相关环境因子及水动力因子进行了同步监测,据此分析了水体层化结构及水动力特性。【结果】神农溪在监测时段内共检测到浮游藻类6门38种(属);库湾浮游藻类生物量时间上差异显著(ANOVA,P<0.05)。春季浮游藻类群落结构具有明显的演替规律,3月份暴发大面积的硅藻水华（藻密度>100×105 cells/L),小环藻(Cyclotella spp.)为优势藻种;4月在SN02–SN06暴发以小球藻(Chlorella spp.)为主要优势种、衣藻(Chlamydomonas spp.)为次优势种的绿藻水华(藻密度>100×105 cells/L),5月份受水位大幅消落影响,浮游藻类生物量降低且无明显优势藻种。【结论】在具备充足的营养盐的水体中,水体层化结构与水动力特性对浮游藻类演替影响重大。三峡水库水位处于快速消落阶段时,流速成为抑制神农溪库湾藻类生长的主要因素。     

The dominant attached filamentous algae of Georgian Bay,the North Channel and Eastern Lake Huron: Field ecology and biomonitoring potential during 1980

Field investigations during the ice-free period of 1980 confirm that the dominant attached filamentous algae in the Canadian waters of Lake Huron are the green algae Ulothrix zonata and Cladophora glomerata, and the red alga Bangia atropurpurea. It is believed that nutrient availability limits the distribution of these algae, while temperature controls their seasonal periodicity. Because of favourable physical characteristics, the study area represents a vast potential habitat for attached filamentous algae. It is expected that eastern Georgian Bay, in particular, will suffer significant environmental degradation from the growth of Cladophora unless existing phosphorus levels are maintained indefinitely (i.e., < 0.005 mg total P 1^–1). Attached filamentous algae accumulate (10³ to 10⁵ x) a variety of elements primarily in proportion to availability in the surrounding water. The occurrence of maximum algal metal concentrations at municipal waste water outfalls, river mouths and harbour areas (e.g., in µg g^–1, Cr 29.0, Cu 46.4, Ni 34.0, Pb 55.0) is indicative of discrete source loadings, while elevated levels at remote sites in eastern Georgian Bay (e.g., in µg g^–1, Cr 12.0–15.5, Cu 18.0, Ni 15.0–16.0, Pb 8.5–8.8) are suggestive of generalized loadings from the Canadian Shield, possibly due to the effects of acidic precipitation.     

Mortality of Herring Eggs on Different Algal Substrates (Furcellaria spp. and Cladophora spp.) in the Baltic Sea – An Experimental Study

In the Baltic Sea, herring (Clupea harengus membras) spawns in the littoral zone, where its eggs are attached to algae or vascular plants. Field studies indicate that egg mortality can be very high (up to 100%) in eggs that are attached to red algae (Rajasilta et al., 1989, 1993). Because high mortality can be due to allelochemical effects of the algae, we studied the mortality of herring eggs on different algal substrates experimentally. Four types of substrates were tested: fresh Cladophora and Furcellaria, and Furcellaria that had decomposed six days or 23 days. The incubation time in the experiments was 3 days and incubation temperature 12–13 ^oC (ca. 700–800 h-degrees). The results were in accordance with observations made in field studies and indicated significant differences among the substrate types. In eggs attached to fresh Cladophora, mortality was significantly lower (mean=2.8%; n=20) than in those attached to Furcellaria, independently of the treatment of the algae. The highest values of mortality (mean=14.4%; n=20) were found in eggs attached to Furcellaria that had decomposed over a six days’ period. This suggested that Furcellaria contain some chemical substances, which can cause mortality in herring embryos and the effect seems to be dependent on the state of decomposition of the algae.     

Exploration and determination of algal role as Bioindicator to evaluate water quality – Probing fresh water algae

ObjectivesTo explore the algal floral diversity and its role to determine water quality.MethodsThe regular monthly collection of algal and water samples was made during 2018. Unicellular algae were preserved in 2 to 3% formalin while macroalgae in 4% formalin. Microphotographs of algae were taken at the biotechnological Lab of PCSIR Lahore, Pakistan. Palmer pollution index was used to determine water quality.ResultsThe study identified 201 algal species distributed among 57 genera, 42 families, 25 orders, 10 classes and 7 divisions. The total score of Algal Genus Pollution Index of Banjosa Lake, Ali Sojal Dam, Dothan Dam, Drake Dam and Rawalakot Nullah (city) were 14, 9, 10, 18 and 25 respectively. It was revealed that Banjosa Lake has probable organic pollution, Ali Sojal Dam and Dothan Dam showed lack of organic pollution, Drake Dam indicated moderate pollution while Rawalakot Nullah (City) indicated confirm high organic pollution.ConclusionWe strongly recommend the conservation and managed status of algal species for sustainable resource of algal- derived products in future. It was revealed that the water quality of Banjosa Lake, Drak Dam and Rawalakot Nullah was affected from anthropogenic activities and needs to be managed.     

Exploration and determination of algal role as Bioindicator to evaluate water quality – Probing fresh water algae

ObjectivesTo explore the algal floral diversity and its role to determine water quality.MethodsThe regular monthly collection of algal and water samples was made during 2018. Unicellular algae were preserved in 2 to 3% formalin while macroalgae in 4% formalin. Microphotographs of algae were taken at the biotechnological Lab of PCSIR Lahore, Pakistan. Palmer pollution index was used to determine water quality.ResultsThe study identified 201 algal species distributed among 57 genera, 42 families, 25 orders, 10 classes and 7 divisions. The total score of Algal Genus Pollution Index of Banjosa Lake, Ali Sojal Dam, Dothan Dam, Drake Dam and Rawalakot Nullah (city) were 14, 9, 10, 18 and 25 respectively. It was revealed that Banjosa Lake has probable organic pollution, Ali Sojal Dam and Dothan Dam showed lack of organic pollution, Drake Dam indicated moderate pollution while Rawalakot Nullah (City) indicated confirm high organic pollution.ConclusionWe strongly recommend the conservation and managed status of algal species for sustainable resource of algal- derived products in future. It was revealed that the water quality of Banjosa Lake, Drak Dam and Rawalakot Nullah was affected from anthropogenic activities and needs to be managed.     

Benthic algal response to hyporheic-surface water exchange in an alluvial river

We studied the response of benthic algae to points of hyporheic-surface water exchange in the main channel of the Middle Fork Flathead River within the Nyack Flood Plain, Montana. We examined hyporheic exchange at 120 sites using piezometers and measuring vertical hydraulic gradient (VHG), hydraulic conductivity, and vertical discharge. We removed benthic algae from a single cobble at each site, and we used VHG to group sampling sites for statistical analysis. Algal cell density and chlorophyll a concentration were significantly higher at sites with hyporheic discharge (+VHG, upwelling) compared to both sites with hyporheic recharge (−VHG, downwelling) and sites with no hyporheic-surface water exchange (=VHG, neutral) (ANOVA, P < 0.05). The assemblages of algae at upwelling sites were also significantly different from downwelling and neutral exchange sites (ANOSIM, P < 0.05). Filamentous green algae Stigeoclonium sp. and Zygnema sp. and a chrysophyte, Hydrurus foetidus (Villars) Trevisan were abundant at upwelling sites, whereas an assemblage of diatoms Achnanthidium minutissimum (Kützing) Czarnecki, Cymbella excisa Kützing, Diatoma moniliformis Kützing, and Gomphonema olivaceoides Hustedt, were the most abundant taxa at downwelling and neutral exchange sites, occurring attached to, or in close association with the stalks of Didymosphenia geminata (Lyngbye) Schmidt. These data show that benthic algal communities are structured differently depending on the direction of hyporheic flux in the main channel of a large alluvial river, suggesting that hyporheic-surface exchange may influence the spatial distribution of main-channel benthic algae in rivers with hyporheic-surface water connectivity. Handling editor: J. Padisak     

A PRELIMINARY LIMNOLOGICAL INVESTIGATION OF TWELVE SOUTHERN AFRICAN GEOTHERMAL WATERS

SUMMARY

The ionic composition and algal flora of twelve geothermal waters in southern South West Africa and north-western South Africa are described, many for the first time. Water temperatures ranged from 24,9 to 66 °C and salinity values indicated moderate mineralization. A trend of increasing sodium and sulphate dominance with increasing water temperature was evident. Green algae were confined to springs with low water temperatures (below 31 °C) while diatoms and blue-green algae were recorded in all the springs, at temperatures up to 66 °C. Flexibacteria (Chlcroflexus) were recorded only in the hotter springs, above 40 °C.     

An evaluation of supplementing bacterial filtration with algae scrubbers in a recirculating marine aquarium

The 4.5 m² algae scrubbers were shown to have no significant impact on the amount of attached or suspended algae in the 30,000 liter display or on the concentrations of ammonia, nitrite, nitrate, phosphate, or dissolved oxygen in the water. Algae scrubbers significantly raised the water's copper concentration. The month-long experiment was conducted in the Coral Reef Tank at the Omaha Zoo.     

Direct Comparison of Phosphate Uptake by Adnate and Loosely Attached Microalgae within an Intact Biofilm Matrix

We report a direct comparison of phosphate uptake by adnate and loosely attached microalgae in an intact biofilm matrix, with resolution at the level of individual cells. Track scanning electron microscope autoradiography enabled assay of [³³P]phosphate uptake from the overlying water by adnate algae left undisturbed on mature leaves of the macrophyte Potamogeton illinoensis or on artificial plant mimics. The epiphyte communities developed in either phosphate-poor or moderately phosphate-enriched water, and they were assayed on both natural and artificial plants. All adnate taxa examined from both natural and artificial plants in both habitats took up significantly less radiolabel when assayed beneath the overlying matrix than when they were exposed to the water upon removal of the overstory material. Track scanning electron microscope autoradiography and track light microscope autoradiography were intercalibrated to enable comparison of [³³P]phosphate uptake by adnate and loosely attached components of the epiphyte matrix. Loosely attached cells on substrata from both habitats took up significantly more radiolabel than did underlying adnate cells, indicating that access to phosphate supplies from the water depended on the position of microbial cells in the matrix. In this short-term assay, the adnate microalgae were relatively isolated from the water column nutrient source.     

Seasonal monitoring of coral–algae interactions in fringing reefs of the Gulf of Aqaba, Northern Red Sea

This paper presents seasonal in situ monitoring data on benthic coverage and coral–algae interactions in high-latitude fringing reefs of the Northern Red Sea over a period of 19 months. More than 30% of all hermatypic corals were involved in interaction with benthic reef algae during winter compared to 17% during summer, but significant correlation between the occurrence of coral–algae interactions and monitored environmental factors such as temperature and inorganic nutrient availability was not detected. Between 5 and 10-m water depth, the macroalgae Caulerpa serrulata, Peyssonnelia capensis and filamentous turf algae represented almost 100% of the benthic algae involved in interaction with corals. Turf algae were most frequently (between 77 and 90% of all interactions) involved in interactions with hermatypic corals and caused most tissue damage to them. Maximum coral tissue loss of 0.75% day⁻¹ was observed for Acropora-turf algae interaction during fall, while an equilibrium between both groups of organisms appeared during summer. Slow-growing massive corals were more resistant against negative algal influence than fast-growing branching corals. Branching corals of the genus Acropora partly exhibited a newly observed phenotypic plasticity mechanism, by development of a bulge towards the competing organism, when in interaction with algae. These findings may contribute to understand the dynamics of phase shifts in coral reefs by providing seasonally resolved in situ monitoring data on the abundance and the competitive dynamic of coral–algae interactions.     

Vertical distribution of the snow alga Chlamydomonas nivalis (Chlorophyta,Volvocales)

Summary Chlamydomonas nivalis commonly forms large blooms, visible as a red coloration, in the snow during summer. Fewer algae are seen in the top layer of snow during days of intense sunlight than on cloudy days. The present experiments were done to investigate this change of vertical distribution of algae. Apparently the algae are able to associate with the watersurface surrounding snow crystals. Due to this association they avoid being washed away by the water from melting snow. Intense sunlight, however, decreases the degree to which the algae associate with the water-surface, and thereby increasing the number of algae being removed from the top layer of snow by the melting water. If the weather becomes cloudy again, the algae do not move upwards, but stay attached to the water-surfaces. Thus when the snow above melts, they will reappear in the top layer.     

The resistance to heat of thermo-resistant streptococci attached to stainless steel in the presence of milk

Skim milk residues had a significant impact on the sensitivity to heat of a dairy isolate of the thermo-resistant, Streptococcus thermophilus. Cells of S. thermophilus (H) suspended in water or in milk had D values at 60°C of 2.0 and 14 min, respectively. Cells of S. thermophilus (H) attached to stainless steel in the presence of water or milk had D values at 60°C of 2.2 and 8.1 min, respectively. The attached cells in both experiments were heat-treated in the presence of water. The increase in heat resistance could not be fully attributed to individual components (caseinate or whey) in the milk. The potential for thermo-resistant streptococci to survive heat treatment in a dairy manufacturing plant is therefore greater than may be expected for the organism in less complex environments. Journal of Industrial Microbiology & Biotechnology (2002) 28, 134–136 DOI: 10.1038/sj/jim/7000229 Received 06 September 2001/ Accepted in revised form 17 November 2001     

Green algae as a structural element of phytoperiphyton communities in streams of NW Russia

Observations were made on the development and distribution of phytoperiphyton communities in 66 lake-river systems in NW Russia from Lake Ladoga to the Barents Sea. In total, 130 genera and 648 species were identified from different substrates, belonging to Cyanophyta (19.1%), Bacillariophyta (59.6%), Chlorophyta (18.7%), and algae from other orders (2.6%). In all streams diatoms dominated by species richness, but they were surpassed by green algae in terms of biomass. The green algae ranged from small planktonic forms to large filamentous species and produced easily visible algal communities. Among the planktonic forms the desmids were the most diverse group. They occurred in attached communities of all rivers and, while never abundant, were widespread. The attached community’s biomass was dominated by green algae. Among these, the filamentous algae Mougeotia sp., Oedogonium sp., Zygnema sp., Spirogyra sp. and Ulothrix zonata exhibited mass development in streams. Their distribution was patchy in the basin, with a total cover varying from less than 1% to 90% of the stream bottom. In some river stretches the diversity and predominance of green algae could be due, in part, to poorly developed riparian canopies. The term periphyton adopted here follows the definition of Odum (1971): “Assemblages which include both plant and animal organisms growing attached to submerged objects”. The prefix phyto- is added to indicate that of the whole biocoenoses only phototrophs are considered in this study. Presented at the International Symposium Biology and Taxonomy of Green Algae V, Smolenice, June 26–29, 2007, Slovakia.     

The effect of benthic algae on phosphorus exchange between sediment and overlying water in shallow lakes: a microcosm study using 32P as a tracer

Sediments are of key importance in determining the nutrient levels of water in shallow lakes as they can act as either source or sink for phosphorus (P) depending on environmental conditions, sediment characteristics, and external nutrient loading. We examined the role of benthic algae in the P cycling between sediment and overlying water in experiments using ³²P as a tracer. Sediment and water samples were collected from Huizhou West Lake, a shallow, eutrophic waterbody located in Huizhou City, South China. Laboratory cultured benthic algae were transferred to cover the sediment core in tubes. When ³²P was added to the water in experimental tubes containing sediment cores with and without benthic algae, ³²P activity after 48 h was significantly lower in the tubes with algae, indicating that benthic algae removed P from the overlying water. When the tracer was injected into the sediment, ³²P activity in the water overlying sediment with benthic algae was substantially lower than in tubes with naked sediment, suggesting that benthic algae reduce the release of sediment P. Oxygen levels were significantly higher in the upper 3 mm of the sediments covered by benthic algae; thus, we hypothesized that oxygen produced by the algae helps inhibit the release of P from the sediment. Our study demonstrates that benthic algae are capable of reducing P levels in water overlying the sediment, suggesting that loss of benthic algae during eutrophication triggered by impoverished light conditions may accelerate the shift in shallow lakes from a clear water to a turbid state.     

Primo contributo alla conoscenza dei laghi appenninici meridionali di alta quota. Il fitoplancton dei laghi del massiccio del Monte Sirino (Appennino Lucano)

Abstract

A preliminary account on some mountain lakes of the Southern Apennines. Phytoplankton investigation on three ponds of the Monte Sirino (Basilicata).—Phytoplankton standing crop and species composition have been studied in three ponds of the Southern Apennines. The observations carried out throughout ten months in 1975, showed a great number of species present in the Remmo pond, mainly diatoms, desmids, green algae, and blue-green algae. In the Sirino pond only diatoms and Chrysophyceae were present.

In comparison, in the Zapano pond, the phytoplankton was scarcely represented but the occurrence of some species of green algae may suggest a eutrophic water condition. On the basis of the peculiarities both of species composition and biomass, the major water bodies may be considered oligotrophic.     

An automated 3D-printed smartphone platform integrated with optoelectrowetting (OEW) microfluidic chip for on-site monitoring of viable algae in water

A sudden increase of algae and their associated toxins in aquatic ecosystems can detrimentally affect the quality of the water, causing serious socio-economic and public health problems. To prevent the spread of harmful algae in aquatic ecosystems, it is essential to track the water’s quality through rapid and in-situ monitoring systems. Conventional methods of algae quantification such as microscopy, hemocytometry, and UV–vis spectroscopy, however, are often unsuitable or inconvenient for in-situ assessment as they require skilled labor and expensive equipment. In this study, we developed a three-dimensional (3D)-printed smartphone platform integrated with a light-driven microfluidic chip operated by optoelectrowetting (OEW). This OEW-driven microfluidic chip not only allows multiplexed drop-wise functions such as droplet transportation, merging, mixing, immobilization on a detection zone, for on-chip water sample preparation but also fluorescent detection and counting of target algae cells using a commercially-available smartphone. Two freshwater algae (C. reinhardtii and M. aeruginosa) and two marine water algae (Amphiprora sp and C. closterium) were employed to validate the 3D-printed smartphone platform in this study. The fluorescence images of viable algae and the cell counting from the microfluidic chip were comparable to the results from a hemocytometer (P > 0.05). We have further conducted tests with spiked samples using freshwater and marine water that were directly collected from environmental samples, showing the same order of magnitude of cell numbers in the spiked and control cultures of algae cells (10⁶ cell/mL, P > 0.05). Unlike traditional quantification methods, the 3D-printed smartphone platform integrated with the OEW offers a highly portable, user-friendly, low-cost tool that enables simple on-chip sample preparation and detection of viable algae. Thus, this stand-alone technology has the potential for rapid and in-situ monitoring of water quality, while using the smartphone’s wireless communication capabilities to report the quality of the water in real-time.     

Scope for use of stable carbon isotopes in discerning the incorporation of forest detritus into aquatic foodwebs

Stable isotope analysis of carbon has been proposed as a means for discerning the incorporation of terrestrial forest detritus into aquatic foodwebs, and as such, has the potential to be used as a biomonitor of the aquatic effects of riparian deforestation. A synthesis of ¹³C/¹²C data from the literature indicates, however, that the scope for successful use of carbon isotope analysis in separating allochthonous and autochthonous food provenance is much more limited than was once thought. This occurs due the overlap in carbon isotope ratios between terrestrial forest detritus and those of both lotic attached algae and lentic filamentous attached algae. Only within rockyshored, oligotrophic lakes without macrophytes, and forest-fringed estuaries and lagoons, where the carbon isotope ratios for attached algae and forest detritus are significantly different, is there any likelihood of discerning the incorporation of allochthonous carbon into aquatic foodwebs using ¹³C/¹²C values alone.