B. Lustigman

Antibiotic production by marine algae isolated from the New York/New Jersey coast

The objective of this research was to undertake a screening of macroalgae from the New York/New Jersey coast for the production of antimicrobials

Effect of aluminum and pH on the growth of Anacystis nidulans

Anacystis nidulans is a typically rod-shaped unicellular cyanobacterium. It is an obligate photoautograph whose photosynthetic apparatus is very is very similar to eukaryotic chloroplasts in functional and molecular aspects. Of the toxic materials discharged, trace and heavy metals are of major concern. Metals are introduced into the environment by industrial agricultural and municipal wastes as well as by natural runoff. Metals emitted into the environment from combustion can also find their way into waterways. Aluminum is one of the most abundant metals in the earths crust. It is reported that water draining from rock strata associated with coal seams may contain acid salts of aluminum, iron and manganese. The toxic effects of aluminum on plant growth have long been known. Several concentrations of aluminum, as well as various pH values were studied, to determine the extent to which some pollutants will effect the growth of Anacystis nidulans. Since reports have indicated that EDTA influences the effect of many metals, studies were performed with and without EDTA.

Effects of nickel and pH on the growth of Chlorella vulgaris

Chlorella is a spherical, unicellular, eukaryotic green algae. It is an obligate photoautotrophy containing chlorophylls a and b. It is a frequent symbiont of many other organisms such as paramecium, hydra and sponges and is important in fresh and marine environments, as well as in the soil. For these reasons, it has been suggested that Chlorella be used for metabolic studies as an indicator of environmental pollution. Ability of microorganisms to grow in environments containing high levels of toxic metals is frequently due to the organisms` capacity for adsorption of these ions and the role that they may play as essential cofactors in metalloenzymes as is the case for nickel. The purpose of this study was to determine the effect of nickel on the growth of Chlorella vulgaris. 19 refs., 4 figs., 1 tab.

Effects of Cobalt and pH on the Growth of Chlamydomonas reinhardtii

Chlamvdomonas reinhardtii is a typical unicellular, spherlcal, green algae containing a large chloroplast, two anterior flagella, and chlorophylls a and b. It is an important organism in several diverse environments, mainly fresh water and soil (Bold & Wynne, 1985). As producers, they have great importance in food chains and the accumulation of heavy metals at various trophic levels of algae, higher plants and animals might affect man ( Kelly, 1988). The study of organisms, such as Chlamvdomonas, can provide an indication of the toxic effects of a pollutant on general metabolic processes, as well as acting as an indicator of the level of pollution in the environment. Algae, more than other groups of organisms, may yield information from experimental simulations that have predictive value for field situations. Organisms at higher trophic levels are more complex and not as easily studied (Stokes, 1984). Previous studies have indicated that dependent upon the organism and the test system employed ranging from prokaryotes to eukaryotes, different sensitivities to metal toxicity will be demonstrated (Codina et al., 1993).

Effect of lead and cobalt on the growth of Anacystis nidulans

Lead is toxic to most living things at high exposure and there is no demonstrated biological need. The limit for lead in drinking water as set by US Public Health Service if 0.05 ppm. Previous reports have indicated that algae are not as sensitive to lead as many other organisms. Chelating agents, such as EDTA (Ethylene Diamine Tetraacetic Acid) are able to reduce the toxicity of lead and other metals. In natural habitats this may be due to the effect of reducing agents and amino acids. PH value has been reported to influence the effect of metals. Cobalt is a relatively rare metal produced primarily as a by-product of other metals, chiefly copper. It is used in high temperature alloys and in permanent magnets. Its salts are used in paint dryers as catalysts, and in the production of pigments. Cobalt has been shown to inhibit chlorophyll biosynthesis and the site inhibition by cobalt has been identified. In this study the effect of lead and cobalt on the growth of Anacystis nidulans will be studied.

Comparison of antibiotic production from four ecotypes of the marine alga, Dunaliella

Coastal waters provide an environment which is abundantly rich in nutrients and biomass. The environmental pressures on these regions are par t icu lar ly intense. Many pol lutants, including human sewage and industr ial wastes, are added to coastal waters providing nutrients and increasing the microbial population. One mechanism for species survival in a highly competitive si tuat ion is the release of bioactive metabolites. I t is a stratagem to f a c i l i t a t e survival and overcome competition found in te r res t r ia l and marine vegetation (Norris and Fenical 1982).

Effect of mercury and cadmium on the growth of Anacystis nidulans

Anacystis nidulans is a member of the cyanobacteria, one of the largest and most diverse groups in the prokaryotic kingdom. Cyanobacteria are excellent organisms to serve as models for the investigation of a wide variety of biological problems such as acting as environmental pollution indicators. There have been several studies on the effects of heavy metals on A. nidulans. Some of these elements, such as copper, are known to be essential nutrients for cyanobacteria. Others, like cadmium, are not known to be necessary for normal growth and metabolism. Large amounts of either essential or non-essential elements can be toxic. Toxic metals, such as mercury and cadmium are a major water pollution problem. Metals come from natural weathering processes of the earths crust, industrial discharge, pest or disease control agents applied to plants, urban run-off, mining, soil erosion, sewage effluents, air pollution fallout and other sources. This study investigates the growth of Anacystis under different concentrations of mercury and cadmium. 13 refs., 2 figs.

Induction of temperate cyanophage AS-1 by heavy metal – copper

BackgroundIt has been reported that some marine cyanophage are temperate and can be induced from a lysogenic phase to a lytic phase by different agents such as heavy metals. However, to date no significant reports have focused on the temperate nature of freshwater cyanophage/cyanobacteria. Previous experiments with cyanophage AS-1 and cyanobacteria Anacystis nidulans have provided some evidence that AS-1 may have a lysogenic life cycle in addition to the characterized lytic cycle.ResultsIn this study, the possible temperate A. nidulans was treated with different concentrations of heavy metal-copper. CuSO4 with concentrations of 3.1 × 10-3 M, 3.1 × 10-4 M, 3.1 × 10-5 M and 3.1 × 10-6 M were used to detect the induction of AS-1 from A. nidulans. The population of the host, unicellular cyanobacteria Anacystis nidulans, was monitored by direct count and turbidity while the amount of virus produced was derived from plaque forming units (PFU) by a direct plating method. The ratio of AS-1 release from A. nidulans was also determined. From these results it appears that AS-1 lysogenic phage can be induced by copper at concentrations from 3.1 × 10-6 M to 3.1 × 10-4 M. Maximal phage induction occurred at 6 hours after addition of copper, with an optimal concentration of 3.1 × 10-6 M.ConclusionCu2+ is a significant inducer for lysogenic cyanobacterial cells and consequently would be a potential control agent in the cyanobacteria population in fresh water ecosystems.

Enhancement of pigment concentrations in Dunaliella tertiolecta as a result of copper toxicity

The addition of copper to coastal waters through the disposal of complex effluents has been increasing. Copper is a well known algicide. It binds to the cell membrane, effects permeability mechanisms and attaches to SH groups on vital enzymes. The ability of algae to withstand copper toxicity varies greatly. The green flagellate, Dunaliella tertiolecta has previously been shown to be highly resistant to copper. Its ability to withstand high concentrations of copper promotes growth of Dunaliella in coastal waters contaminated with increased copper concentrations. Dunaliella tertiolecta possesses chlorophylls a and b, small amounts of alpha- and greater amounts of beta-carotene as well as neoxanthin, zeaxanthin and lutein. This study was undertaken to determine the effect of lethal and sublethal concentrations of copper on the growth and production of chlorophyll and carotenoids in Dunaliella tertiolecta.

Effect of increasing copper and salinity on glycerol production by Dunaliella salina.

Copper is an essential trace element needed in small quantities by algae for plastocyanin production. However, at high concentrations it acts as an effective algiclde, Lethality due to copper is greatest with high activity of free cupric ions (