Witwatersrand Microbiology Project Field Manual

 

 

 

 

 

 

 

 

 

 

by

 

Duane P. Moser

pACIFIC nORTHWEST nATIONAL lABORATORY

 

S.M. PfiffneR

uNIVERSITY OF tENNESSEE

 

A.Welty

Northern Arizona university

 

j. wARD

UNIV. OF TORONTO

 

T.C. ONSTOTTand J. HALL

pRINCETON uNIVERSITY

 

 


Table of contents

 

 

Benches and Workspaces………………………………………………..…1

 

PReparation of equipment…………………………………………………1

 

FIELD KITS CHECK LIST.........................................……………………….…...…5

 

BOREHOLE WATER SAMPLING...........................................…………………….5

 

SAMPLE PROCESSING: PRESSURE FILTRATION........................................….10

 

PRESERVATION OF WATER SAMPLES………………………………………..12

 

ONLINE FIELD NOTEBOOK……………………………………………………..13

 

INOCULATION OF ANAEROBIC MEDIA………………………………………13

 

FIGURES …………………………………………………………………………..14

 

APPENDIX 1: GAS SAMPLING PROCEDURE ………………………………...17

 

APPENDIX 2: D.I. WATER (Labcon Waterstill System)………………………….20

                        PROPER USE OF A SUB-ZERO FREEZER……………………....20

 

 

 

 

 

 


 

Benches and Workspaces

 

The field lab is open to the outside air.  In winter a considerable load of dust accumulates on surfaces.  In the summer, mold spores, pollen, etc. are a threat to general lab cleanliness.  As a matter of routine, it is strongly recommended that before any lab work that you spray down bench surfaces with Mr. Muscle or equivalent cleaner and wipe down with paper towel.

 

 

PReparation of SAMPLING equipment

 

All equipment that comes in contact with samples must be cleaned thoroughly between applications.  The risk of cross contamination is to some extent reduced by autoclaving, but good lab hygiene is still strongly encouraged. Equipment that is autoclaved and stored wrapped will remain sterile for a long time, provided the equipment is dry.  Even autoclaved equipment stored wet is prone to moldy growth (an obvious source of contamination).  As a general rule of thumb, equipment should be cleaned and stored in such a manner, as you would be comfortable EATING from it.

 

MATERIALS:

 

1.      Vacuum pump

2.      Ar or N2 high pressure gas cylinders with sterile filter and tubing

3.      Autoclave

4.      Bunsen burner

5.      Sterile gloves

6.      Al foil

7.      Cornelius canisters

8.      Sampling manifold (pre-methanol rinsed and autoclaved)

9.      Sampling tubing

10.  Packers

11.  Serum vials

12.  Needles

13.  50 ml Falcon tubes for FISH samples

14.  Filter forceps

15.  Flame and ethanol for flaming forceps and canister quick connects

16.  15 ml falcon tube for anions

17.  15 ml falcon tube with 1.5 ml of concentrated nitric acid for cations.

 

 

HOSES/QUICK DISCONNECTS:  There are four hoses used in sampling.  Two have quick connects at both ends.  One quick connect attaches it to the Cornelius canister and the other to the sampling manifold.  The other two hoses have quick connects for the sampling manifold at one end and syringes at the other end.  Hoses are easy to overlook as sources of contamination between samples. The insides of hoses are out of sight (and mind) and also difficult to clean.  Worse, the inside surfaces of hoses come into intimate contact with samples both in the field and lab.  Contaminated hoses are very efficient means to transfer contamination into an otherwise pristine sample, thus hoses deserve special care.

 

After every use, hoses must be thoroughly rinsed out first with soapy water (hold ends and slosh around).  Soap can be delivered from a squirt bottle. This is followed by rinsing with clean tap water, then DI and finally a small amount of HPLC grade methanol to assure that samples are of PLFA quality.  Hoses attached to the female end of quick disconnects (e.g. Cornelius) may in some circumstances be left attached for cleaning provided that the plunger (Figure 1) is depressed to permit the inside of the disconnect to be washed along with the hose.  If you really want to be sure, remove the disconnect every time and clean it separately.  It is very easy to leave wash (or sample) water in dead spaces within valves and fittings where unwanted microbes can grow to considerable density and lead to the unwitting contamination of samples.

 

Once clean, wind them up, autoclave them and keep them in their autoclave bag until at the sampling site underground.

 

FILTER/PACKER MANIFOLDS:  These must be thoroughly cleaned between samples.  Remove all filter housings and open all valves.  Clean out with a bottlebrush and use soapy water for an initial cleaning.  Rinse well with DI water and final with HPLC grade MeOH.  Allow to air dry and autoclave with the valves open.  Packer manifold male quick connect ends need not be removed every time, but valve should be propped open and the various prescribed rinses performed.  Keep wrapped in autoclave bag with tape until underground at borehole sampling site.

 

BOREHOLE PACKERS:  After a great deal of experimentation, three major types of borehole packers have become standard equipment. Types 1 and 2 (See figure 2) are adaptations of locally available steel telescopic packers produced by CEM Engineering of South Africa. Both types seal the hole using exactly the same approach.  A threaded wrench is used to apply end pressure on a series of rubber disks, which expand and seal the hole. Water and gas are forced to travel through the interior of the packer, either inside the bore of the packer itself or through a plastic liner.

 

Type 1 uses the standard steel packer (various sizes 1 inch up to 80 mm) commonly used in the mines, but with an all plastic insert designed by George Rose of Princeton University to remove the influence of metal in the sampling system.  Type 1 (2 sizes) packers are the most useful in lower flow situations and where high confidence gas samples are required.

 

Type 2, employs either the standard steel telescopic packer design or a stainless steel version constructed by CEM Engineering on special order.  The latter version is generally used for high flow situations and fits the largest of the sampling manifolds in our collection.

 

Type 3 is the expansion drain plug version.  This employs a commercially available plastic drain plug (United States Plastics, Inc.), which is fitted into the smaller of the two sizes of sampling manifolds (3/4” I.D.) via a plastic adaptor constructed for this purpose in the Princeton University shop.  A custom-made Teflon washer (white) is useful to prevent leakage between the commercial drain plug and the adaptor. All packer supplies are kept in the corner cabinet behind the main lab door or in one of the small parts toolbox labeled packers. 

 

It is essential to assemble the packer you intend to use underground prior to autoclaving and understand how the system works.  Then wrap up packer and handle in autoclave bags, autoclave and keep in autoclave bag until you are ready to use them underground at sampling site.

 

CORNELIUS CANISTERS:  In many ways, these are your most critical piece of equipment.  These must be cleaned well between samplings not only to negate the potential for cross contamination, but also to assure that corrosive samples do not damage these canisters. 

1.      Empty canisters are first dissembled to facilitate cleaning.  Both outlets are removed with the proper box-end wrench and the straw is removed from the outlet and cleaned. Be sure to note that the straw is used only on the outlet side. The canister is rinsed with normal tap water, and then washed with lab soap and a long handled bottlebrush to remove all visible particulates from the prior sampling. Next, the canister is rinsed with DI water several times, as are the straw and other parts. 

 

2.      The canister is reassembled and about 100 ml of HPLC grade methanol or absolute ethanol is added and the screw cap tightened down.  The fittings for the inlet and outlet are different.  The inlet fittings have an indentation cut into nut portion of the fitting.  With the alcohol inside, the canister is sloshed around with care to cover all inside surfaces.

 

3.      It is essential to clean the inside of the straw and outlet Cornelius fittings (black) with alcohol as well.  Adding a slight over pressure to the canister using a bike pump or Ar or N2 gas cylinders does this.  An adaptor for the former is stored in the lab tool drawer.  The adaptor has a Schrader valve on one end and a gray inlet Cornelius fitting on the other.  Add about 10 pumps with the bicycle pump and then attach the black outlet fitting.  Most of the alcohol will squirt out of the canister rinsing the inside of the water passage as it does so. Finally, invert the canister with the screw lid off and allow the inside to dry.  Drying can be performed by attaching a sterile, clean hose to the canister inlet valve from either the compressed Ar or N2 cylinders and blowing out thru the outlet valve.  Make sure that the hose has an autoclaved filter in line to scrub the Ar or N2. 

 

4.      Once dry and fully assembled, the canisters are refitted with their screw lids and autoclaved.  It is critical to remove the plastic handle on the one canister so equipped, as it will melt in the autoclave.  Black vinyl caps are available in one of the small parts boxes which fit the inlet and outlet couplings perfectly.  These fittings should be capped prior to autoclaving.  The heavy plastic cap should be loose during autoclaving.  Autoclave on dry goods setting at 121oC. 

 

5.      Once the autoclave cycle is finished, remove than canister and tighten the canister lid down.  It is vented, so there is no concern about not being able to remove it later. 

 

6.      Through the OUTLET fitting (fits gray adaptor) attach the clean and filtered Ar line.  Set the second stage of the regulator for 50 kPa. Pull up on the spring-loaded cap vent and lodge it sideways (open position).  Start the Ar flowing and flush the canister for 2 – 5 minutes depending on the flow and level of anaerobicity required.  Note that Ar is heavier than air and filling from the bottom (through the outlet) aids in the displacement of air.  Once the canister is done flushing, close the vent valve by pulling up, turning 90o, and letting the spring pull the valve closed.  Since the Ar line is still running, the canister will develop a pressure of 50 kPa, and can be stored this way until ready to sample.  The seals on these units are of high quality and the pressure will be maintained indefinitely (although a good policy is to check by pulling on the vent valve to see if there is still a positive gas pressure in the canister).

 

7.      It is a good idea to label the canister as being sterile (autoclave tape), clean and Ar filled at this point. You can’t tell by looking at it after all. Leave the black vinyl caps on the quick connect fittings.  These are the only part of the canister that needs to be kept scrupulously clean.  The rest of the outer surfaces can (and will) get dirty due to handling in the mine environment.

 

MICROBIAL SAMPLING SERUM VIALS:  Prepare at least 4 to 6 120 ml serum vials for anaerobic microbial sampling. 

  1. This is done by taking a serum vial, adding a drop of H2O (THIS IS IMPORTANT IN ORDER TO DEACTIVATE SPORES!!)
  2. Then seal with blue butyl rubber stopper and Al cap and crimp Al cap.
  3.  Flush serum vial with filtered N2 gas using sterile hose and needle and use another needle to vent serum vial.  Do this for a couple of minutes. 
  4. Then put autoclave tape on and autoclave. 
  5. After autoclaving, label serum vials with tape marked “BIO” to distinguish them from the gas sampling vials. 

 

HANNA PROBES:  Calibrate probes prior to each sampling trip.  AFTER SAMPLING TRIP MAKE SURE TO RINSE PROBES IN D.I. WATER AND STORE PH PROBE TIP IN STORAGE SOLUTION (THIS IS LOCATED IN REFRIGERATOR).  YOU MUST DO THIS.  IF RESIDUAL SULFIDIC SALINE WATER DRYS ON PROBE IT WILL CORRODE THEM AND THEN THEY’LL NOT FUNCTION PROPERLY.

 

  1. Eh (or ORP) probe.  Use Zobell solution in refrigerator (make sure it is kept in refrigerator). The Eh reading will vary as a function of temperature and probe type (Ag/AgCl, saturated Calomel, or NHE).  If the Hanna probe is a Ag/AgCl (with 4 M KCl filler solution) then Eh = 231 + 1.3 x (25-ToC) in millivolts for the Zobell solution.  If the Hanna probe is a saturated Calomel, then Eh = 185 + 1.64 x (25-ToC) in millivolts for the Zobell solution.  If the Hanna probe is an NHE, then Eh = 428 millivolts at 25oC for the Zobell solution.  SO MAKE SURE YOU KNOW WHAT TYPE OF ELECTRODE YOU HAVE!!  RECORD READING A TEMPERATURE AS IT IS USED TO CORRECT THE FIELD READING.
  2. pH probe.  Use the pH 4, 7 and 10 solutions to calibrate probes. 
  3. Conductivity probe.  Use saline solution to calibrate probe and note the temperature as response is temperature dependant. 

 

FIELD KITS CHECK LIST

(Check Table 1)

 

ICE CHEST: if planning an overnight stay after sampling or a long distance travel

 

AUTOCLAVED GEAR:

 

1.      TWO Cornelius canisters with black caps and filled with Ar or N2 gas.

2.      Sampling manifolds with connectors and can also connect tubing to reduce contamination if borehole is certainty.  All wrapped in autoclave bags.

3.      Long telescoping packers w/ handles and small compression packers, all wrapped in autoclave bags.

4.      TWO x tubes w/ Quick connects and w/ canister connectors

5.      TWO x tubes w/Quick connects and syringe for bio samples

6.      Biosampling Kit:  4 to 6 x 120 ml serum vials w/N2 gas and drop of H2O + 10 x 20.5 gauge needles (big yellow) + 10 x 22.5 gauge needles (smaller)

7.      bag of random tubes, fittings and hose clamps for uncertain borehole situations

8.      ONE 1 liter bottle for service water sample-this can be carried in a portable ice chest

 

MORE BIOSAMPLING GEAR:

 

1.      TWO x 50 ml falcon tubes (Fish)

2.      Biofilm kit-6 x 15 ml falcon tubes + pH strips + plastic bulb syringe + 10 x Cryovials + spatula + surgical gloves

3.      Syringe kit (for no borehole access, just crack)-1 x 60 ml syringe+ 1 x 10 ml syringe+ 10 x syringe needles large and small + stainless steel canola + 2 syringe filters

4.      Sterilization kit-ethanol tube+ chemwipes + latex gloves + tube of bleach

5.      Take mattress pump, Tygon tubing, one or two filter holders, MeOH pre-rinsed forceps, Whirlpack bags, latex gloves, sharpie, two muffled Al foil with glass fiber filters (2 filters per pack).  The glass fiber filters in Al foil pockets are used for ONLY for air sampling and extra muffled Al foil pockets are used to store air samples.  These samples are collected using mattress pump in drawer.  Use Teflon tubing to connect to filter apparatus.  Put holders on the intake to the pump so that air is being pulled through the filter first then into Tygon tubing and into pump.  This avoids contaminating the filters with the pump.  Do two air filters, one for PLFA and one for DNA and a third optional for enrichments and fourth for FISH.

 

FIELD MEASUREMENT GEAR:

1.      Portable Black Plastic Probe kit w/ Hanna pH, temperature, conductivity and Eh probes, Allen key set for packers, pH 4, 7 and 10 solution to check calibration, pH strips.

2.      Thermometer (for back up)

3.      Small plastic beaker

 

CHEMISTRY SAMPLING GEAR:

 

1.         TWO x tubes w/Quick connect for sampling manifold and Leurlock fittings on other end. 

2.         TWO x 1 liter bottles (for 14C, 36Cl, T and d13C organic)

3.         ONE x 500 ml. Nalgene bottle (for phosphorus, partially full, HCl washed)

4.         TWO x 20-40 ml serum vials (for acetate/formate partially full, d18O full, not washed, no preservative)

5.         THREE x 60-120 ml serum vials (for dD-no preservatives, and for d13C DIC and DIC, preservatives added later)

6.         TWO x 60-120 serum vials evacuated (for filtered d15N ammonia, unfiltered d15N ammonia)

7.         TWO x 40-60 ml Quorpak (for S species w/ Zn acetate, TOC+DOC w/HCl or phosphoric acid)

8.         TWO x 60 ml syringes with Leurlocks (for S isotopes on sulfate and sulfide).  Preloaded with 10 ml of Zn acetate, HgCl2 and NaOH solution.

9.         TWO x 15 ml Falcons filtered (cations w/HNO3, Fe w/HCl)

10.     ONE x Nalgene filtered (anions, partially full)

11.     ONE x bag of blue stoppers, Al caps, crimper, 0.2 ΅m syringe filters (to attach to tubes for filtered samples) and small syringe needles.

 

GAS SAMPLING GEAR:

 

1.      TWO x Cu tubes loaded in one rack

2.      ONE x green bag of valve, fittings, and ratchet wrench

3.      ONE x big red bucket

4.      ONE x small plastic beaker with fitting for syringe needle

5.      ONE x big hose

6.      SIX x 120 ml pre-evacuated serum vials

 

TOOL KIT:

Screw driver, spanner, Leatherman tool, tape, sharpies, and Bungie cords. 

 

Everything should fit into 3 large backpacks (Fig. 1b).

 


Table 1. Sample containers, labels and preservatives for geochemistry and microbiology

 

Labeling and preservatives added as indicated below.

Type (Label)

Container

Preservative 

 

Geochemistry filtered 

Anion

0.22΅ filter into a 50ml Nalgene bottle or 15 ml Falcon tube

3/4 fill and freeze 

Cation

0.22΅ filter into a 50ml Nalgene bottle or 15 ml Falcon tube already prepped with HNO3

1 ml conc. HNO3/20 ml sample

Diss. NH3

0.22΅ syringe filter into a 20-60 ml serum vial 

50΅l conc. H2SO4/20 ml sample

Diss. Fe

0.22΅ filter into a 50ml Nalgene bottle or 15 ml Falcon tube prepped with HCl

1 ml conc. HCl/25 ml sample

SPE

ODS, silica, and 2 JW cartridges

On surface: Pass filtrate from DNA/PLFA filters through SPE cartridges, record sample and volume filtered and store in refrigerator or freezer. 

Geochemistry unfiltered

DIC

50 ml amber septum bottle or serum vial

50΅L sat. HgCl2

d13C DIC

 50 ml amber septum bottle or serum vial

 50΅L sat. HgCl2

d15N NH3

20-60 ml serum vial 

50΅L conc. H2SO4/20 ml sample

Formate/acetate

45 ml Teflon septum glass vials or serum vials

partially fill and freeze

DOC

45 ml Teflon septum glass or serum vials

1 ml conc. HCl or Phosphoric acid/25 ml sample

TOC

45 ml Teflon septum glass or serum vials

1 ml conc. HCl or Phosphoric acid/25 ml sample

 d13C DOC

1 L amber glass bottles w/ Teflon caps 

1 ml sat. HgCl2 

Sulfur species

20 ml serum vial

transfer anaerobically into 50΅L 2N ZnAc loaded 5 ml serum vials, partially fill and freeze  

d34S

2 x 60 ml syringes

Preloaded with 10 ml D.I., 500΅L 2N ZnAc, 50΅L sat. HgCl2

d18O

1 x 15-40 ml serum vial

none

dD