Currently, Florida is experiencing an algae epidemic that is threatening the state’s water reservoirs. Instead of using chemicals to control theproblemnowand later contribute to others in the future, natural biomaterials have received attention as alternatives to chemical agents. The algicidal effects of crude and pure rice hull extracts on the growth of Microcystis aeruginosa were investigated using cultured unicellular and colonial strains. Rice hull is the major by-product of milling and represents approximately 20% of rough grain weight. Thus, rice hulls, which are otherwise an agricultural waste product, maybe an environmentally friendly and sustainable source of a bioalgicide.
Upon treatment with rice hull crude extract (RHE), growth inhibition of M. aeruginosa was much higher than anticipated(Park. M, et al. 2009).In Florida saw Palmettos are the most abundant palm in the state, and like rice hulls, the palmetto could act as an algicide. The saw palmetto is most commonly used for decreasing symptoms of an enlarged prostate called benign prostatic hypertrophy (BPH)(Penugonda, Kand Lindshield, B.
2013).In this study, the aim is to investigate positional useful plant compounds or extracts from native Floridian plants that show lysis activity against cyanobacteria. I expect that this study will contribute to the control of pollution by M.aeruginosa and following identification of active compounds for emergencies caused by this application.
Literature review Cyanobacterial blooms in the eutrophic freshwater ecosystems are a major problem worldwide, causing deterioration of water quality, and illness in wildlife, livestock, and humans. Cyanobacteria (blue-green algae) are photoautotrophic gram-negative bacteria that commonly evoke the occurrence of blooms and scums in lakes, reservoirs, slow-flowing rivers, and the production of potent toxins(Rastogi, R, et al.
2015). Microcystis aeruginosa is the common species of bloom causing cyanobacteria, theses cyanobacteria that produce hepatotoxins are termed microcystins, these toxins threaten aquatic organisms and public health. Therefore, M. aeruginosa has been the subject of increasing research. It has been shown that the growth of different cyanobacteria and their toxins biosynthesis is greatly influenced by different abiotic factors such as light intensity, temperature, short-wavelength radiations, pH, and nutrients(Rastogi, R, et al.2015). The increased incidence of toxin cyanobacteria blooms (cyano blooms)in Florida has generated tremendous concern for potential risks to the state’s wildlife, residential and economic health. The economic cost of the largescale reservoir that would redirect the freshwater blooms TotheFloridaevergladesisestimated to run up to 4 billion dollars/annum. Here the run-off water of Okeechobee lake will travel through miles of wet prairies that act like filters that absorb excess nutrients. Advanced approaches or the development of new affordable alternatives are needed to terminate or prevent/suppress the harmful cyanobacterial blooms for environmental sustainability. To minimize the threat, several strategies or approaches such as chemical, physical, biological, and other cognizance approaches came into consideration for mitigating the harmful cyanobacteria bloom incidence. Cyanoblooms can be controlled to a certain extent using some chemicals such as Algicidalcompoundslike: such like copper sulfate, aluminum salts, lime, calcite, chlorine, and low-cytotoxin microgel-Fe(III)(Rastogi, R, et al.2015). These compounds are widely used in industrial water, for the sanitation of swimming pools, and the like. The use of synthetic compounds for bloom control has its limitations, therefore, a range of natural chemicals from diverse organisms have been derived as potent substituents for synthetic.
algaecides. however, this approach may not be effective due to growth inhibitions of other beneficial microalgae, thereby undesirably influencing the aquaticecosystemsThousands of plants worldwide are used in traditional treatments for bacterial infections, and especially traditional Chinese medicinal herbs which contain abundant potential antimicrobial agents have been used for the treatment of a wide variety of diseases for thousands of years. In recent years, screening of plant resources for antimicrobial compounds has been intensively carried on worldwide and is being implemented as algaecides(Yang, J, et al.2009). Native Floridian plants such as the Saw palmetto can be further investigated, to be potential algaecides that are locally available and areanaturalabundant.MethodsCyanobacteria Culture and Saw palmetto Microcystis aeruginosa (FACHB-905) is purchased from the Institute of Hydrobiology, Chinese Academy of Sciences (Wuhan, China) The strains are grown in BG-11 medium that is optimized for cyanobacteria 25 °C with illumination at 3,000 lx under a 16 L/8 D cycle. Saw palmetto is obtained from an authorized source. The different parts of the plant are used such as the leaves, the branches, the fruits, the rhizomes, and the peel preparation of the Extracts Stock solution is prepared with the traditional process currently used in Chinese herbal products by boiling 100g of raw material with 1000mL of distilled water for 1 h. The material is centrifuged and filtered through filter paper. The residue remaining on the paper is arere-boiled.
with 1,000mL distilled water, centrifuged, and filtered. This solution is regarded as a concentration of 100% (100mL of HC solution made from 100g of raw material). After being autoclaved the stock solution was stored at4 °C until used. Measurement of Anticyanobacterial Activity The antimycobacterial activity is determined using the soft-agar overlayer(SAO) method Approximately 5 mL of cyanobacterial cells are mixed with warmed 5 mL of 0.8% (w/v) soft agar and over-layered on a 10 mL of agar layer solidified in a plate. After the cyanobacterium-containing layer is solidified. extract solutions were respectively deposited on the disc, and the concentration of the test herb extracts was diluted to 200 mg/mL. 20 μg/mL CuSO4and distilled water can be used as positive and negative controls, respectively. The plates were incubated. Anticyanobacterial activity can be evaluated by measuring the diameter of the inhibition zone (DIZ) of the tested cyanobacterium.