micropara lab midterms

• What is Inorganic Synthetic Broth consists of?

  S odium chloride (5.0g)

  M agnesium sulfate (0.2g)

  A mmonium dihydrogen phosphate (1.0g)

  D ipotassium hydrogen phosphate (1.0g)

  A tmospheric CO2
• Inorganic Synthetic Broth is prepared by dissolving these salts in 1000 ml of water?

  True
• Glucose Salts Broth: An adaptation of the inorganic synthetic broth?

  True
• Glucose Salt Broths are enriched with glucose(5g per liter) ?

  True
• Glucose Salt Broth: as the sole organic carbon source, enhancing microbial growth by providing essential nutrients alongside the basic inorganic salts?

  True
• These are not chemically defined due to their variable composition?

  Complex Media
• primarily consisting of plant and animal tissue extracts, These media are rich in amino acids, sugars, vitamins, and minerals, supporting the growth of most heterotrophs?

  Complex Media
• A fundamental complex medium with 5.0 g peptone and 3.0 g beef extract per 1000ml of distilled water?

  Nutrient broth
• Peptone serves as a nitrogen source?

  True
• Beef extract provides organic carbon, nitrogen, vitamins, andinorganic salts?

  True
• Enhanced with 5 g of yeast extract per liter, adding to the nutrient broth base. Rich in (Vitamin B)? Suitable for cultivating fastidious microorganisms

  Yeast Extract Broth
• Purposes of Special-Purpose Media?

  Isolation of specific bacterial types

  Differentiation based on macroscopic appearance and biochemical reactions

  Enumeration for sanitary microbiology (e.g., water, sewage, food, dairy)

  Assays for antibiotics, vitamins, industrial products

  Characterization and identification by chemical change production
• It Combines essential nutrients with specific chemicals to support and differentiate bacterial growth, catering to unique metabolic pathways of different bacterial types?

  Special Purpose Media
• Differential/Selective Media?

  Mannitol Salt Agar, MacConkey Agar, Eosin-Methylene Blue Agar (Levine)
• Media that distinguishes Staphylococci through 7.5% NaCl inhibition and mannitol fermentation, indicated by a yellow zone around growth?

  Mannitol Salt Agar
• Media that Isolates gram-negative bacteria, differentiating lactose fermenters (red colonies) from non-fermenters (tan/transparent colonies) using crystal violet, bile salts, and neutral red?

  MacConkey agar
• Media that Identifies gram-negative bacteria, specifically members of the Enterobacteriaceae?

  Eosin-Methylene Blue Agar (Levine)
• E. coli form blue-black colonies with metallic green sheen?

  Enteric Lactose Fermenters
• Produce colorless colonies, appearing purple due to the medium's color; partially inhibits gram-positive organism growth?

  Enteric Non-Lactose Fermenters
• Mannitol Salt Agar is ____ when it can ferment mannitol (positive)?

  Yellow
• Mannitol Salt Agar is ____ when it cannot ferment mannitol (negative)?

  pinkish
• MacConkey Agar: lactose-fermenting-gram-negatives (lactose-fermenters) will form ____ colonies?

  pink
• MacConkey Agar: non-lactose fermenters will form ____ colonies?

  off-white colonies
• What media is supplemented with nutritious materials (e.g.,blood, serum, yeast extract) to cultivate fastidious organisms?

  Enriched media
• Blood agar → uses blood as an enrichment ingredient for cultivating organisms like Streptococcus spp., and to demonstrate hemolytic properties
• Hemolytic Activities: Classified into gamma (no lysis), alpha(incomplete lysis with a greenish halo), and beta (complete lysis with a clear zone) hemolysis, indicating the organism's ability to lyse red blood cells
• Spectrophotometric analysis and serial dilution-agar plate analysis are two primary methods for assessing microbial populations, each offering unique insights into cell viability and density
• Petroff-Hausser Counting Chamber: Specialized thick glass slide with a central chamber 0.02 mm deep, featuring an etched grid with improved Neubauer rulings
• Petroff-Hausser Counting Chamber: The chamber's depth and grid design facilitate accurate eukaryotic cell counting in a suspension, with a volume over a square millimeter of 0.02 mm³
• Petroff-Hausser Counting Chamber: Used extensively for quick counts, including in dairy microbiology for bacterial quantification in milk. However, this method counts both living and dead cells and lacks sensitivity for populations under 1million cells
• Coulter Counter Principle: Utilizes a minute orifice with an electric current to count cells suspended in a conducting fluid
• Rapidly enumerates the number of organisms flowing through, without distinguishing between live and dead cells, or differentiating cells from inert particulate matter?

  Electric Cell Counters
• Chemical Methods: Indirect quantitative analysis through measurements of protein concentration, DNA production, dry weight of cell mass, oxygen uptake, and carbon dioxide production. Useful for estimating bacterial population growth
• Protein Concentration: Indirect measurement of cell growth through increases in protein concentration. Reflects overall biomass and cellular activity
• Dry Weight Estimation: Determines cell mass by measuring the dry weight of a specific culture aliquot. Provides a direct physical measure of growth.
• DNA Production: DNA quantification as an indicator of cellproliferation. Increases in DNA content correlate with celldivision and growth
• Metabolic Parameters: Oxygen uptake and carbon dioxide production as proxies for aerobic and anaerobic growth respectively. Directly proportional to the number of active cells
• It measures the amount of light a sample absorbs. In microbiology, it assesses the turbidity of a culture, correlating it with microbial population size?

  Spectrophotometry
• Serial dilution-agar plate technique is used for accurate determination of viable cell counts, distinguishing living cells from dead ones in a sample
• Serial Dilution Process: Involves diluting a bacterial suspension in sterile water or suitable diluents