摘要:

SUMMARYPit connection formation in the marine red alga Pseudogloiophloeaconfusawas studied with the electron microscope. The process of formation occurs in 2 stages. First, a septum forms as an annular ingrowth from the lateral walls. Lomasomes are associated with the centripetal accretion of wall material. The completed septum contains a large rimmed aperture, bounded by the continuous plasmalemma, and through which the cytoplasm is continuous from cell to cell. In the second stage, a highly structured plug is formed which completely blocks the aperture. The plug is condensed on flattened vesicles which lie parallel to one another and which traverse the aperture.The mature plug is composed of granules 50–100 A in diameter and surrounded by several dense layers which appear to enclose an 80 A limiting membrane. Once the pit connection is formed, no material is seen to traverse i

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02577.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYVitamin‐requiring marine algae, Cyclotella nana, Monochrysis lutheri,andAmphidinium carterae,were grown in batch culture with limiting concentrations of vitamin B12, thiamine, and biotin, respectively. Cell numbers, average cell volumes, biomasses,11CO2uptake rates, and chlorophyll a contents were determined daily. Maximum14CO2uptake rates in most vitamin concentrations were obtained at 2 days withC. nanaandM. lutheriand at 4 days withA. carteraeafter starved cultures were exposed to the vitamin. Radiocarbon uptake rates approximately reflect biomass increases. Cell numbers were proportional to vitamin concentrations when cells were incubated for 2 to 3 more days. Cell sizes varied depending on time of incubation. Chlorophyll a content did not always reflect vitamin concentrations. Maximum carbon assimilation rates (Km) and saturation constants (Ks) determined from14CO2, uptake rates in different vitamin concentrations during early incubation were higher than when determined from cell number in log phase growth. Dissolved vitamin B12, thiamine, and biotin in many samples of seawaters were in the ranges which influence the growth rate, cell size, and chlorophyll a content ofC. nana, M. lutheri,andA. carterae,respectively, in laboratory studies. The effects of vitamins on these algaein situmay be simila

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02578.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe microtubules associated with the pellicle, reservoir and locomotory flagellum ofEuglena granulatawere subjected to rotational analysis using the technique of Markhamet al.The results indicate that the microtubules have 11‐14 subunits when viewed in transverse section. Rotational analysis of the entire locomotory flagellum was also conducted to better demonstrate the nature of the arms extending from the peripheral microtubule

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02579.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYThe algal mats of a number of hot springs in the Lower Geyser Basin of Yellowstone National Park were destroyed by a brief violent hailstorm on August 30, 1967. The rate of recovery of the algal mat at Mushroom Spring was studied by quantitative methods. In the temperature range of 65–71 C a unicellular cyanophycean alga is the sole photosynthetic component. The doubling times during the recovery period for three stations were: Station I (71 C), 17 days; station II (68 C), 10.5 days; station III (65 C), 10 days. The algal mat had returned to apparently normal size by 152 days after the catastrophe. The significance of these observations for the conservation of hot spring communities is discusse

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02580.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYFrom information on pollution‐tolerant algae compiled from reports from 165 authors, the genera and species most often referred to as significant fall into a relatively stable series. Diatoms, pigmented flagellates, green, and blue‐green algae are all well represented among the pollution‐tolerant genera and species. The top 8 genera areEuglena, Oscillatoria, Chlamydomonas, Scenedesmus, Chlorella, Nitzschia, Navicula,andStigeoclonium,and the top 5 species, Euglena viridis, Nitzschia palea, Oscillatoria limosa, Scenedesmus quadricauda,andOscillatoria tennis.In some genera, e.g., Euglena,a single species is far more significant than all others as a pollution‐tolerant form. In other genera, e.g., Oscillatoria,only a slight difference distinguishes the pollution tolerance of 2 or more species. Algal genus and species pollution indices arc presented for use in rating water samples with high organic po

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02581.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYA defined medium was developed for a bacterizedGladophora glomeratafrom Lake Michigan yielding 0.8 g dry weight/m2/20 days and a doubling time of 1.2 days. Best growth was at 25 C under continuous aeration and 200–500 ft‐c light. Aeration with 2% CO2, with or without THIS buffer, inhibited growth. Calcium nitrate, urea, and NaNO3were all utilized as nitrogen sources; however, more NO3nitrogen was required than urea or Ca nitrate N for maximum yields. Germination of zoospores through zoosporangial walls was obser

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02582.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

摘要:

SUMMARYExtracts of the marine ciliateCyclotrichium meuniericontained chlorophylls a and c, carotenoids, and a phycoerythrin with a single absorbance maximum at 542 nm. This assemblage of pigments suggests that the numerous photosynthetic symbionts present in each ciliate cell belong to the Cryptophyceae.

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02583.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY

ISSN:0022-3646    

DOI:10.1111/j.1529-8817.1969.tb02584.x

出版商:Blackwell Publishing Ltd    

年代:1969

数据来源: WILEY