Primary culture of bovine mammary acini on a collagen matrix

Lactating bovine mammary epithelial acini were isolated and primary culture on rat tail attached collagen gels are described. Acini rapidly attach to the gels and morphologically change little over days of culture under the culture conditions described herein. Cells release lactose, alpha-lactalbumin and alpha-s1 casein over a 6-day period. A new HPLC method for measuring lactose in mammary cell culture media is described. Comparisons of acini cultures with individual cell cultures show acini to be 1.5-5 times more productive than cells in secreting lactose and casein, respectively.     

Dynamic suspension culture for scalable expansion of undifferentiated human pluripotent stem cells

Human pluripotent (embryonic or induced) stem cells (hPSCs) have many potential applications, not only for research purposes but also for clinical and industrial uses. While culturing these cells as undifferentiated lines, an adherent cell culture based on supportive layers or matrices is most often used. However, the use of hPSCs for industrial or clinical applications requires a scalable, reproducible and controlled process. Here we present a suspension culture system for undifferentiated hPSCs, based on a serum-free medium supplemented with interleukins and basic fibroblast growth factor, suitable for the mass production of these cells. The described system supports a suspension culture of hPSC lines, in both static and dynamic cultures. Results showed that hPSCs cultured with the described dynamic method maintained all hPSC features after 20 passages, including stable karyotype and pluripotency, and increased in cell numbers by 25-fold in 10 d. Thus, the described suspension method is suitable for large-scale culture of undifferentiated hPSCs.     

Erythroid precursors studied by mouse bone marrow cultivation in a plasma clot]

Two types of erythroid precursors were found by cultivation of the mouse bone marrow in the plasma clot with mouse serum and without adding exogenic erythropoietin to the culture medium. The first precursor had properties similar to the erythroid colony-forming unit (CFUe) previously described while the second resembles in its properties the erythroid burst-forming unit (BFUe). Optimal concentration of mouse serum in the culture medium was 10-15%. Clone nature of the colonies and bursts described is confirmed by linear dependence of their number on the cell concentration in the culture.     

Isolation of Mycobacterium Paratuberculosis from Sheep and Cattle in Iceland

Isolation of Mycobacterium paratuberculosis from sheep and cattle in Iceland. Acta vet. scand. 1979, 20, 191–199. — Culture experiments concerning the Icelandic variant of Mycobacterium paratuberculosis are described. Various decontaminating agents and culture media were employed and the colonial morphology of freshly isolated strains on different media described. The growth rate and culture requirements are compared with those of the Norwegian goat-pathogenic variant of M. paratuberculosis. For primary isolation modified Herrold’s medium gave the best results. However, on all the various culture media used, the growth of the Icelandic variant was much more sporadic than that of the Norwegian goatpathogenic variant. It is concluded that bacteriological culture is not useful for the diagnosis of Johne’s disease caused by the Icelandic variant of M. paratuberculosis.     

Apparatus for the Maintenance of Bacterial Cultures in the Steady State : II. Improved turbidity control and culture cell

(1) A more convenient method for maintaining constant turbidity in the culture cell is described. (2) An improved culture cell and cell wipers which do not cause foaming are described.     

Characterization of a highly enriched dehalococcoides-containing culture that grows on vinyl chloride and trichloroethene

A highly enriched culture that reductively dechlorinates trichloroethene (TCE), cis-1,2-dichloroethene (cDCE), and vinyl chloride (VC) to ethene without methanogenesis is described. The Dehalococcoides strain in this enrichment culture had a yield of (5.6 +/- 1.4) x 10(8) 16S rRNA gene copies/micromol of Cl(-) when grown on VC and hydrogen. Unlike the other VC-degrading cultures described in the literature, strains VS and BAV1, this culture maintained the ability to grow on TCE with a yield of (3.6 +/- 1.3) x 10(8) 16S rRNA gene copies/micromol of Cl(-). The yields on an electron-equivalent basis measured for the culture grown on TCE and on VC were not significantly different, indicating that both substrates supported growth equally well. PCR followed by denaturing gradient gel electrophoresis, cloning, and phylogenetic analyses revealed that this culture contained one Dehalococcoides 16S rRNA gene sequence, designated KB-1/VC, that was identical (over 1,386 bp) to the sequences of previously described organisms FL2 and CBDB1. A second Dehalococcoides sequence found in separate KB-1 enrichment cultures maintained on cDCE, TCE, and tetrachloroethene was no longer present in the VC-H(2) enrichment culture. This second Dehalococcoides sequence was identical to that of BAV1. As neither FL2 nor CBDB1 can dechlorinate VC to ethene in a growth-related fashion, it is clear that current 16S rRNA gene-based analyses do not provide sufficient information to distinguish between metabolically diverse members of the Dehalococcoides group.     

比利时杜鹃的组织培养研究

以比利时杜鹃 (Rhododendronhybridun)的茎段、叶为材料 ,Read、Anderson和N培养基为基本培养基 ,在 2 3± 0 .5℃ ,光照 12h/d ,光照强度 15 0 0lx下进行培养 ,诱导出芽。结果表明N培养基为比利时杜鹃组织培养的最适培养基     

凤梨科植物的离体培养（综述）

本文主要从快速繁殖,育种探索和种质保存三个方面介绍凤梨离体培养研究的进展,并简要介绍其他凤梨科植物离体培养的研究概况,在此基础上对一些问题进行探讨并提出展望。     

Penicilliopsis pseudocordyceps, the holomorph of Pseudocordyceps seminicola, and notes on Penicilliopsis clavariaeformis

Penicilliopsis pseudocordyceps was collected from seeds of Diospyros discolor and is described as new. The anamorph produced in culture is Pseudocordyceps seminicola. The teleomorph was produced on oatmeal agar in 6 wk. Penicilliopsis clavariaeformis was also collected from the same seeds, yielding its Sarophorum palmicola anamorph in culture.     

The production of mycobacterial antigens by homogeneous culture in a fermentor

Mycobacterium bovis strain BCG, substrain 1173P2, has been grown in homogeneous culture in classical synthetic Sauton medium without supplementary ingredients. The culture conditions are described. The protein release in the culture medium and the tuberculin yield after 2% trichloroacetic acid precipitation were significantly improved. The antigenicity of the tuberculin has been successfully assayed on specifically sensitized guinea-pigs. It is concluded that homogeneous mycobacterium culture in a fermentor using synthetic medium is a suitable method for the large scale production of antigen.     

Induction and cultivation of a stable L-form of Bacillus subtilis

The induction of L-forms of Bacillus subtilis from protoplasts is described. The method involved the frequent subculture of the unstable L-form on a growth medium supplemented with lysozyme and horse serum. A stable culture, which did not revert when lysozyme and horse serum were omitted from the medium, was obtained after 13 subcultures. This culture could be grown on solid and in liquid medium by routine microbiological methods. Long-term storage of these cells was achieved by freeze drying and maintenance in glycerol at -70 degrees C. The cultural adaptability of the L-form is described and discussed with respect to methods of cultivation and growth.     

杂交瘤细胞的大量培养

杂交瘤细胞的大量培养是一项迅速发展的技术。本文评述了杂交瘤细胞培养条件和代谢调控方面的研究进展,包括反应器培养中的过程参数优化、细胞损伤和保护、营养物质利用和有害副产物的形成、细胞生长和单抗分泌的动力学以及长期培养的稳定性等问题。同时,本文也讨论了在生物反应器中培养杂交瘤细胞的操作模式和控制策略的研究工作,特别是近年来备受重视的灌注培养和补料培养。     

Induction and cultivation of a stable L-form of Bacillus subtilis

The induction of L-forms of Bacillus subtilis from protoplasts is described. The method involved the frequent subculture of the unstable L-form on a growth medium supplemented with lysozyme and horse serum. A stable culture, which did not revert when lysozyme and horse serum were omitted from the medium, was obtained after 13 subcultures. This culture could be grown on solid and in liquid medium by routine microbiological methods. Long-term storage of these cells was achieved by freeze drying and maintenance in glycerol at −70°C. The cultural adaptability of the L-form is described and discussed with respect to methods of cultivation and growth.     

A Rapid Method for In Situ Staining of Prostatic and other Tissue Culture Cells

A rapid method for staining prostatic epithelium grown in vitro and other tissue culture cells is described. Giemsa stain and a phosphate buffer with a pH of 6.8 were used. Excellent nuclearcytoplasmic contrast is obtained with this procedure. It is recommended for studies on the general morphology of normal and abnormal cells in tissue culture.     

Continuous culture of mixed oral flora on hydroxyapatite-coated glass beads.

Methods for initiating and perpetuating a culture of mixed oral flora on hydroxyapatite (HT)-coated glass beads are described. Preliminary characterization of the resultant flora showed that species common in human dental plaque were present. The composition of the flora could be manipulated by altering cultural conditions. Scanning electron micrographs demonstrated that the microbes grew in densely packed microcolonies on the surface of the HT bead. A procedure for continuous culture of colonized HT beads in glass columns is described. This technique should make it possible to utilize experimental protocols employing continuous or interrupted flow of materials.     

Continuous culture of mixed oral flora on hydroxyapatite-coated glass beads.

Methods for initiating and perpetuating a culture of mixed oral flora on hydroxyapatite (HT)-coated glass beads are described. Preliminary characterization of the resultant flora showed that species common in human dental plaque were present. The composition of the flora could be manipulated by altering cultural conditions. Scanning electron micrographs demonstrated that the microbes grew in densely packed microcolonies on the surface of the HT bead. A procedure for continuous culture of colonized HT beads in glass columns is described. This technique should make it possible to utilize experimental protocols employing continuous or interrupted flow of materials.     

A method for the rapid and precise determination of acclimated phytoplankton reproduction rates

A rapid method for measuring, simultaneously, the asexual reproductionrates of hundreds of phytoplankton cultures is described. Thismethod is based on the dairy measurement of in vivo chlorophyllfluorescence read directly in the culture tubes. Hundreds ofthese culture tubes, containing specially prepared culture medium,can be maintained in identical environments in specially designedconstant environment devices. The method is capable of measuringthe acclimated reproduction rates of phytoplankton cultureswith an error of 3–4% (coefficient of variation). Completeacclimation, crucial to the detection of small genetic differencesbetween clones, takes one to three weeks, thus necessitatinglong-term experiments. Studies using the methods described indicatethat, in a constant environment, coccolithophores and dinoflagellatesreproduce at constant rates, but diatoms do not.     

Continuous Culture of Ruminal Microorganisms in Chemically Defined Medium: I. Design of Continuous-Culture Apparatus

An apparatus is described which has been used for successful continuous culture of the ciliates from the rumen of cattle. Automatic control of feeding rate, pH, oxidation-reduction potential, temperature, stirring rate, aeration rate, salinity, and volume of the culture is provided for, using standard commercial equipment, whenever possible. The operation of this apparatus is described.     

流加发酵提高产胡萝卜素红酵母产量的研究

本文对产胡萝卜素的红酵母进行了间歇、恒速及变速流加发酵实验,建立了简单的数学模型控制流加。实验结果表明,变速流加可显著地提高红酵母的产量,当流加控制因子K为88×10－5,变速流水发酵比间歇发酵红酵母产量提高了56．2％。     

大规模动物细胞培养的问题及对策

大规模动物细胞培养在生物技术产业化进程中显示出强大的潜力。本文综述了大规模动物细胞培养过程中出现的问题及其解决办法 ,包括细胞培养环境、基因工程途径改建细胞系及过程监控等。对于这些进展的充分了解对优化细胞培养工艺、提高产品质量具有重要意义